A

#include <bits/stdc++.h>
using namespace std;

int main() {
    int t;
    cin>>t;

    while(t--){
        int n;
        cin>>n;

        vector<int> a(n);
        for(auto &e: a)     cin>>e;

        int ans=0, chk=0;

        for(int i=0; i<n; i++)
        {
            if(a[i] == i+1)
            {
                ans += (chk == 0);

                if(chk == 0)        chk = 1;
                else                chk = 0;
            }
            else
                chk = 0;
        }

        cout<<ans<<"\n";
    }
}