#include<bits/stdc++.h> using namespace std; int main(){ char s1[1001]; char s2[1001]; int a1=0,a2=0; cin>>s1>>s2; while(s1[a1]!='\0'){ a1++; } while(s2[a2]!='\0'){ a2++; } if(a1==a2){ for(int i=0; i<a1; i++) { if(s1[i]!=s2[i]) { cout<<"no"<<endl; break; } else{ cout<<"yes"<<endl; } } } return 0; }