#include<bits/stdc++.h> using namespace std; char s1[1001]; char s2[1001]; int main(){ cin >> s1; cin >> s2; int la = strlen(s1); int lb = strlen(s2); if(la != lb) { cout << "no"; } else{ for(int i = 0;i<=la-1;i++) { if(s1[i] != s2[i]) { cout << "no"; return 0; } } cout << "yes"; } return 0; }