#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
char s1[501],s2[501];
int main()
{ 
    double x,len,k;
    int i;
    cin>>x;
    scanf("%s",s1);
    scanf("%s",s2);
    len=strlen(s1);
    for( i=0;i<len;i++)
    {
    	if(s1[i]==s2[i])
    	{
    		k++;
		}
	}
	if(double(k)/len>=x)
	{
		cout<<"yes";
	}
	else
	{
		cout<<"no";
	}
}

#include<bits/stdc++.h>

using namespace std;

char s[1000],m[1000];

int main()

{

double a,k=0;

cin>>a;

cin>>s;

cin>>m;

for(int i=0;i<strlen(s);i++)

{

	if(s[i]==m[i])

	  k++;

	else

	continue;

}

int t;

double g;

t=strlen(m);

g=k/t*1.00;

if(g>=a)

cout<<"yes";

else

cout<<"no";

return 0;

}