#include<bits/stdc++.h> using namespace std; int main(){ /** int n,x,y; cin>>n>>x>>y; if(y/x>=n){ cout<<0; }else{ if(y % x ==0) cout<<n - y/x; else cout<<n -y/x-1; }**/ int a,x,y; cin>>a>>x>>y; if(a>='x' && a<='y'){ cout<<"yes"; }else cout<<"no"; return 0; }