/*  This Code is Submitted by wywcgs for Problem 1680 on 2006-03-03 at 14:38:41 */ 
#include <cstdio>

const int MAX = 32;

int main()
{
	int lmt[MAX][MAX], g, l;
	int i, j, t;
	
	for(i = 0; i < MAX; i++)
		for(j = 0; j < MAX; j++)
			if(i == 0) lmt[i][j] = 0;
			else if(j == 0) lmt[i][j] = i;
			else lmt[i][j] = lmt[i-1][j]+lmt[i-1][j-1]+1;
	for(t = 1; scanf("%d %d", &g, &l) != EOF && !(g == 0 && l == 0); t++)
		printf("Case %d: %d\n", t, lmt[g][l]);
	
	return 0;
}