#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ char a[151],b[151]; cin>>a>>b; for(int i=0;a[i]!='!0' && b[i]!='\0';i++){ if(a=='\0' && b!='\0'){ cout<<"no"; return 0; } else if(a[i]!='\0' && b[i]=='\0'){ cout<<"no"; return 0; } cout<<"yes"; return 0; }