AC

#include <iostream>
using namespace std;
int main()
{
int t;
cin>>t;
while (t--)
{
int n,m;
cin>>n>>m;
int a=0,x=0;
for (int i=1;i<=n;i++)
{
cin>>x;
a+=x;
}
if (m-a>0)
cout<<0<<endl;
else
cout<<a-m<<endl;
}
return 0;
}