#include <stdio.h>
int F[33][33] = {0};

int getF(int G, int L){
	if(G < 0 || L < 0) return 0;
	int jyAns = F[G][L];
	if(jyAns > 0) return jyAns;
	if(G == 1){
		F[G][L] = 1;
		return 1;
	}
	if(G < L) return getF(G, G);
	int ans = 1 + getF(G-1, L-1) + getF(G-1, L);
	F[G][L] = ans;
	return ans;
}

int main() {
	int G, L, cnt = 1;
	while(1){
		scanf("%d%d", &G, &L);
		if(G == 0) return 0;
		printf("Case %d: %d\n", cnt, getF(G, L));
		cnt++;
	}
	return 0;
}