//minamoto

 #include<bits/stdc++.h>

 #define mp(i,j) make_pair(i,j)

 using namespace std;

 #define getc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)

 char buf[<<],*p1=buf,*p2=buf;

 template<class T>inline bool cmax(T&a,const T&b){return a<b?a=b,:;}

 inline int read(){

     #define num ch-'0'

     char ch;bool flag=;int res;

     while(!isdigit(ch=getc()))

     (ch=='-')&&(flag=true);

     for(res=num;isdigit(ch=getc());res=res*+num);

     (flag)&&(res=-res);

     #undef num

     return res;

 }

 const int N=;

 vector<int> a[N];int n,f[N];map<pair<int,int>,int> x;

 vector<int>::iterator ii;

 int main(){

 //    freopen("testdata.in","r",stdin);

     n=read();

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

         int l=read(),r=read();

         ++l,r=n-r;

         if(l>r) continue;

         if(++x[mp(l,r)]==) a[r].push_back(l);

     }

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

         f[i]=f[i-];

         for(ii=a[i].begin();ii!=a[i].end();++ii)

         cmax(f[i],f[(*ii)-]+min(i-(*ii)+,x[mp(*ii,i)]));

     }

     printf("%d\n",n-f[n]);

     return ;

 }