#include <iostream>
#include <cstdio>
#include <utility>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
#include <queue>
#include <cmath>
#include <set>
#include <stack>

#define test
#ifndef test
    freopen("in.in", stdin);
#endif

#define rint register int
#define ll long long
#define P pair<char, int> 
const int N = 5e5 + 50;

using namespace std;
int arr[N];
bool dic[N];
void solution(){
    int n; scanf("%d", &n);
    for(int i = 1; i <= n; i++) dic[i] = false;
    int ans = 0;
    for(int i = 1; i <= n; i++){
        int tmp; scanf("%d", &tmp);
        if(!dic[tmp + 1]) ans++;
        dic[tmp] = true;
    } 
    printf("%d", ans);
}

int main(){
    test
    int t = 1;
    scanf("%d", &t);
    while (t--){
        solution();
        if(t) printf("\n");
    }
}