#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

const int INF = 0x6fffffff;

int n, a;
double b;
double res;

double f(double m, double M) {
	return (m - M) / (1 + pow(m - a, b));
}

double gao(double M) {
	int i, j, k;
	int tc(200);
	int left, right, mid1, mid2;
	double ret(-1), t1, t2;

	left = a, right = INF;
	while (tc--) {
		mid1 = left + (right - left) / 3;
		mid2 = mid1 + (right - left) / 3;
		
		t1 = f(mid1, M), t2 = f(mid2, M);
		ret = max(ret, max(t1, t2));
		if (t1 < t2) left = mid1 + 1;
		else right = mid2 - 1;
	}
	return ret + M;
}

int main() {
	int i, j, k;
	int tc, cn(0);
	double M, m;

	while (3 == scanf("%d %d %lf", &n, &a, &b)) {
		res = M = a;
		for (i=1; i<n; ++i) res = max(res, M = gao(M));
		printf("Case %d: %.2lf\n", ++cn, res);
	}
	return 0;
}