#include <bits/stdc++.h>
using namespace std;

#define all(x) (x).begin(),(x).end()
#define SP <<" "<<
#define MOD 1000000007
#define IINF 1000000000
#define LINF 1000000000000000000

typedef long long LL;
typedef long double LD;

int main(){
  cout << "yes" << endl;
  return 0;
}