TIJIE

#include <iostream>
using namespace std;
int main()
{
    double a,sum;
    string s1,s2;
    cin>>a>>s1>>s2;
    for(int i=0;i<s1.size();i++)
    {
        if(s1[i]==s2[i]) sum++; 
    }
    if(sum/s1.size()>=a) cout<<"yes";
    else cout<<"no"; 
    return 0;
}