usaco 2.3 money...自娱自乐版...

/*
    ID:chenjiong
    PROG:money
    LANG:C++
*/

#include <stdio.h>
#include <string.h>

int V,N;
int m[30];
int sum;
long long cnt;

void dfs(int cur,int s)
{
    if ( sum > N ) 
        return;
    if ( sum == N )
    {
        cnt++;
        return;
    }
    int i;
    for ( i = s; i < V; i++)
    {
        sum += m[i];
        dfs(cur + 1,i);
        sum -= m[i];
    }
}

int main()
{
    freopen("money.in","r",stdin);
    freopen("money.out","w",stdout);

    int i;
    scanf("%d%d",&V,&N);
    for ( i = 0; i < V; i++)
        scanf("%d",&m[i]);

    sum = 0;
    dfs(0,0);

    printf("%ld\n",cnt);

    return 0;
}