24 lines
367 B
C++

#include<cstdio>
#define MAXN 5001
#define MAXM 51
int a[MAXM],f[MAXN];
int n;
int main(void)
{
scanf("%d",&n);
for (int i=0;i<n;i++)
scanf("%d",&a[i]);
int sum=0;
f[0]=1;
for (int i=0;i<n;i++)
{
sum+=a[i];
for (int j=sum;j>=a[i];j--)
f[j]+=f[j-a[i]];
}
if (sum%2==1) puts("0");
else printf("%d\n",f[sum/2]/2);
return 0;
}