#include<bits/stdc++.h> using namespace std; int main() { int sum = 0; char a[1001],b[1001]; cin >> a >> b; int n = strlen(a); int m = strlen(b); if(n!=m) { cout << "no"; }else{ for(int i = 0; i < n; i++) { if(a[i]==b[i]) { sum++; } } if(sum==n) { cout << "yes"; }else{ cout << "no"; } } return 0; }