View Code of Problem 104

#include<iostream>
#include<iomanip>
using namespace std;
int main() {
	int n, v1, v2, t;
	while (cin >> n>> v1 >> v2 >> t) {
		n *= 1000;
		if (t*(v2 - v1) > -n) 
			cout << "NO" << endl;
		else
			cout <<fixed<<setprecision(2)<<(double)n / (v1 - v2) << endl;
	}
}