#include<cmath>
#include<cstdio>
#include<iomanip>
#include<iostream>
using namespace std;
int main() {
	int i, p, q, r, s;
	while (scanf("%d %d %d %d", &p, &q, &r, &s) == 4) {
		long double ans = 0;
		if (p - q < q)
			q = p - q;
		if (r - s < s)
			s = r - s;
		for (i = 1; i <= q; i++)
			ans += log(p - q + i) - log(i);
		for (i = 1; i <= s; i++)
			ans -= log(r - s + i) - log(i);
		printf("printf: %.5lf", exp(ans));
		cout << "\tcout: " << fixed << setprecision(5) << exp(ans) << endl;
	}
	return 0;
}