View Code of Problem 104

#include<stdio.h>
#include<math.h>
int main(){
	int n,v1,v2,t;
	double time;
	while(scanf("%d%d%d%d",&n,&v1,&v2,&t)!=EOF){
		if(v1<=v2){
			printf("NO\n");
		}else{
			time=n*1000.0/(v1-v2);
			if(time<=t){
				printf("%.2lf\n",time);
			}else{
				printf("NO\n");
			}
		}
	}
	return 0;
}