#include <bits/stdc++.h>   using namespace std;   const int mx = 1e6;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int t;     cin >> t;     while (t--) {       long long n, h;       cin >> h >> n;       long long arr[n];       for (int i = 0; i < n; i++) cin >> arr[i];       long long ans = 0, cp = h;       for (int i = 1; i < n; i++) {         if (cp == 0) break;         if (cp == (arr[i] + 1)) {           if ((i + 1) < n && cp == (arr[i + 1] + 2)) {             cp = arr[i + 1];             ++i;           } else {             if ((i + 1) < n) {               cp = arr[i + 1] + 1;               ++ans;             } else if (i == n - 1) {               if (cp == 2)                 continue;               else                 ++ans;             }           }         } else {           cp = arr[i] + 1;           --i;         }       }       cout << ans << endl;     }   }   