#include<bits/stdc++.h>

using namespace std;

int n,k,cnt[] = {};

string s;

int main()

{

    ios::sync_with_stdio();

    cin >> n >> k >> s;

    for(int i = ;i < s.length();i++)   cnt[s[i]-'a']++;

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

    {

        if(cnt[i] > k)

        {

            cout << "NO" << endl;

            return ;

        }

    }

    cout << "YES" << endl;

    return ;

}

#include<bits/stdc++.h>

using namespace std;

int n,a[];

int main()

{

    ios::sync_with_stdio();

    cin >> n;

    int cnt = ;

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

    {

        cin >> a[i];

        if(a[i]%)  cnt++;

    }

    if(cnt > )   cout << "First" << endl;

    else    cout << "Second" << endl;

    return ;

}

#include<bits/stdc++.h>

using namespace std;

int n,a[],ans[];

struct xx

{

    int x,id;

    friend bool operator <(xx a,xx b)

    {

        return a.x > b.x;

    }

}b[];

int main()

{

    ios::sync_with_stdio();

    cin >> n;

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

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

    {

        cin >> b[i].x;

        b[i].id = i;

    }

    sort(a+,a++n);

    sort(b+,b++n);

    for(int i = ;i <= n;i++)   ans[b[i].id] = a[i];

    for(int i = ;i <= n;i++)   cout << ans[i] << " ";

    cout << endl;

    return ;

}

#include<bits/stdc++.h>

using namespace std;

int n,m,a[],vis[] = {},dep[] = {};

struct xxx

{

    int to,id;

    xxx(int a,int b):to(a),id(b){};

};

vector<xxx> v[];

vector<int> ans;

bool dfs(int now,int pre)

{

    vis[now] = ;

    for(int i = ;i < v[now].size();i++)

    {

        int t = v[now][i].to;

        if(t == pre || vis[t])    continue;

        if(dfs(t,now))

        {

            dep[now]++;

            ans.push_back(v[now][i].id);

        }

    }

    if(a[now] ==  && dep[now]% ==  || a[now] ==  && dep[now]% == )    return ;

    return ;

}

int main()

{

    ios::sync_with_stdio();

    cin >> n >> m;

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

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

    {

        int x,y;

        cin >> x >> y;

        v[x].push_back(xxx(y,i));

        v[y].push_back(xxx(x,i));

    }

    int ok = ;

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

    {

        if(a[i] == -)

        {

            dfs(i,);

            ok = ;

            break;

        }

    }

    if(!ok && dfs(,))

    {

        cout << - << endl;

        return ;

    }

    cout << ans.size() << endl;

    for(int i = ;i < ans.size();i++)   cout << ans[i] << " ";

    cout << endl;

    return ;

}