#include <iostream>

using namespace std;

int main(){
int X;
int Y;
int N;
double r;
cin >> X; 
cin >> Y;
cin >> N;
cin >> r;
double x = (double)X;
int months = N*12;
double monthlyRaise = (1 + r/1200);
double diference = 0;
double x2 = 0;
double y = (double)Y;
while (X != 0){
  for (int i = 0; i < months; i++){
  x2 = x*monthlyRaise;
  diference = x2 - x;
  x = x2 - Y;
  if (diference > y){
  i = months;
  x = 10; // proste kladne
  }
  
  }
  if(x > 0){
  cout << "NO\n";
  }
  else{
  cout << "YES\n";
  }
    
  
  cin >> X; 
  cin >> Y;
  cin >> N;
  cin >> r;
  months = N*12;
  monthlyRaise = (1 + r/1200);
  x = (double)X;
  y = (double)Y;
}
  return 0;
}