View Code of Problem 104

#include<stdio.h>
#include<string.h>
#include<math.h>
 
int main(){
	double n,v1,v2,t;

	while(scanf("%lf%lf%lf%lf",&n,&v1,&v2,&t)){
	
		double time;
		if(v1>v2){
			time=1000*n/(v1-v2);
			if(time>t)printf("NO");
			else printf("%.2lf",time);
		}
		else printf("NO");
	}


}