#include <stdio.h>
#include <math.h>
#define MONTHS 12

int main(void){
  int debt, monthly_pay, years, total_salary;
  float r;
  double total_debt, r_m, total_r;
  
  while(1){
    scanf("%d %d %d %f", &debt, &monthly_pay, &years, &r);
    if(debt == 0 && monthly_pay == 0 && years == 0 && r == 0){
      break;
    }
    total_salary = MONTHS * years * monthly_pay;
    
    r_m = 1 + r/(MONTHS * 100);
    total_r = pow(r_m, years * MONTHS);
    total_debt = debt * total_r;
    if(total_salary < total_debt){
      printf("NO\n");
    } else {
      printf("YES\n");
    }
  }
  return 0;
}