#include<bits/stdc++.h>

 using namespace std;

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define sqr(x) ((x)*(x))

 #define pb push_back

 #define maxn 1000005

 typedef long long ll;

 typedef unsigned long long ull;

 int main(){

     #ifndef ONLINE_JUDGE

       //  freopen("input.txt","r",stdin);

     #endif

     std::ios::sync_with_stdio(false);

     map<int,int>mp;

     for(int i=;i<=;i++){

         mp[i*(i+)/]=;

     }

     int n;

     cin>>n;

     if(mp[n]) cout<<"YES"<<endl;

     else cout<<"NO"<<endl;

 }

 #include<bits/stdc++.h>

 using namespace std;

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define sqr(x) ((x)*(x))

 #define pb push_back

 #define maxn 1000005

 typedef long long ll;

 typedef unsigned long long ull;

 struct sair{

     char ch;

     int v;

     bool operator<(const sair &b)const{

         return v>b.v;

     }

 }s;

 int main(){

     #ifndef ONLINE_JUDGE

         freopen("input.txt","r",stdin);

     #endif

     std::ios::sync_with_stdio(false);

     int a,b,c;

     string str;

     map<char,int>mp;

     mp['A']++;

     mp['B']++;

     mp['C']++;

     for(int i=;i<=;i++){

         cin>>str;

         if(str[]=='>'){

             mp[str[]]++;

         }

         else{

             mp[str[]]++;

         }

     }

     vector<sair>ve;

     int book[];

     memset(book,,sizeof(book));

     for(map<char,int>::iterator it=mp.begin();it!=mp.end();it++){

         s.ch=it->first;

         s.v=it->second;

         if(book[s.v]){

             cout<<"Impossible"<<endl;

             return ;

         }

         book[s.v]=;

         ve.push_back(s);

     }

     sort(ve.begin(),ve.end());

     for(int i=;i<ve.size();i++){

         cout<<ve[i].ch;

     }

 }

 #include<bits/stdc++.h>

 using namespace std;

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define sqr(x) ((x)*(x))

 #define pb push_back

 #define maxn 1000005

 typedef long long ll;

 typedef unsigned long long ull;

 vector<string>ans;

 string s[];

 bool add(char &a,char b){if (a!='.'&&a!=b)return ;a=b;return ;}

 int main(){

     #ifndef ONLINE_JUDGE

         freopen("input.txt","r",stdin);

     #endif

     std::ios::sync_with_stdio(false);

     for (int i=;i<=;i++)cin>>s[i];

     sort(s,s+);

     do{

         vector<string>v(s[].size(),string(s[].size(),'.'));

         if (s[].size()!=s[].size()+s[].size()-) continue;

         if (s[].size()!=s[].size()+s[].size()-) continue;

         bool fl=;

         for (int i=;i<s[].size();i++)fl&=add(v[i][s[].size()-],s[][i]);

         for (int i=;i<s[].size();i++)fl&=add(v[s[].size()-][i],s[][i]);

         for (int i=;i<s[].size();i++)fl&=add(v[][i],s[][i]);

         for (int i=;i<s[].size();i++)fl&=add(v[i][],s[][i]);

         for (int i=;i<s[].size();i++)fl&=add(v[s[].size()-+i][s[].size()-],s[][i]);

         for (int i=;i<s[].size();i++)fl&=add(v[s[].size()-][s[].size()-+i],s[][i]);

         if (!fl)    continue;

         if (ans.empty()||v<ans)    ans=v;

     }while (next_permutation(s,s+));

     if (ans.empty())    cout<<"Impossible"<<endl;

         else for(auto i:ans) cout<<i<<endl;

 }

 #include<bits/stdc++.h>

 using namespace std;

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define sqr(x) ((x)*(x))

 #define pb push_back

 #define maxn 1000005

 typedef long long ll;

 typedef unsigned long long ull;

 char s[][];

 int c[],n,m,ans;

 void dfs(int t)

 {

     int i,j;

     for(i=;i<m;i++)

         if(c[i]<)return ;

     if(t>=n)

     {

         for(i=;i<m;i++)

             if(c[i]>) return ;

         ans++;

         return ;

     }

     for(i=;i<=;i++)

     {

         for(j=;j<m;j++)

             if(s[j][t]==(i+''))c[j]--;

         dfs(t+);

         for(j=;j<m;j++)

             if(s[j][t]==(i+''))c[j]++;

     }

 }

 int main(){

     #ifndef ONLINE_JUDGE

         freopen("input.txt","r",stdin);

     #endif

     std::ios::sync_with_stdio(false);

     cin>>n>>m;

     for(int i=;i<m;i++)cin>>s[i]>>c[i];

     ans=;

     dfs();

     cout<<ans<<endl;

 }

 #include<bits/stdc++.h>

 using namespace std;

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define sqr(x) ((x)*(x))

 #define pb push_back

 #define maxn 1000005

 typedef long long ll;

 typedef unsigned long long ull;

 const double g=9.8;

 double v,al[],ss[],cc[];

 int d[];

 pair<double,double> w[];

 double x[];

 double run(double x,double alpha)

 {

     return (v*sin(alpha)+v*sin(alpha)-g*x/(v*cos(alpha)))*x/(v*cos(alpha))/;

 }

 bool cmp(const int &a,const int &b)

 {

     return al[a]<al[b];

 }

 int main(){

     #ifndef ONLINE_JUDGE

         freopen("input.txt","r",stdin);

     #endif

     std::ios::sync_with_stdio(false);

     int n,m;

     scanf("%d%lf",&n,&v);

     for(int i=;i<=n;i++)

         scanf("%lf",&al[d[i]=i]),cc[i]=cos(al[i]),ss[i]=sin(al[i]);

     sort(d+,d++n,cmp);

     scanf("%d",&m);

     for(int i=;i<=m;i++)

         scanf("%lf%lf",&w[i].first,&w[i].second);

     sort(w+,w++m);

     int j=;

     for(int i=;i<=n;i++)

     {

         while(j<=m&&run(w[j].first,al[d[i]])>w[j].second)j++;

         if(j>m||run(w[j].first,al[d[i]])<)

         {

             x[d[i]]=v*ss[d[i]]/g**v*cc[d[i]];

             continue;

         }

         x[d[i]]=w[j].first;

     }

     for(int i=;i<=n;i++)

         printf("%.9lf %.9lf\n",x[i],run(x[i],al[i]));

 }