#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, t, m, n;
  cin >> t;
  int arr[t];
  for (i = 0; i < t; i++) {
    int sum = 0, k = 0;
    cin >> n >> m;
    int arr1[n];
    for (int j = 0; j < n; j++) {
      cin >> arr1[j];
      if (j != 0) sum += arr1[j];
    }
    k = arr1[0];
    while (k < m) {
      if (sum != 0) {
        k++;
        sum--;
      } else
        break;
    }
    arr[i] = k;
  }
  for (i = 0; i < t; i++) cout << arr[i] << "\n";
}
