#include<iostream> #include<bits/stdc++.h> using namespace std; int main(){ double b; string a,a1; cin>>b>>a>>a1; int sum=0; for(int i=0;i<a.size();i+=1){ if(a[i]==a1[i]){ sum+=1; } } if(1.0*sum/a.size()>=b){ cout<<"yes"; } else{ cout<<"no"; } }