#include <stdio.h>
#define MONTHS 12

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