View Code of Problem 104

#include<iostream>
using namespace std;
int main(){
	int n, v, y,t;
	while(cin>>n>>v>>y>>t){
		n*=1000;
		if(t*(v-y)<n) 
			cout<<"NO\n";
		else
			printf("%.2f\n",n*1.0/(v-y));
	}
}