#include <bits/stdc++.h> using namespace std; void mainSolve() { int N; cin >> N; string str=""; cin >> str; int c =0; for(int i=0;i<N;i++){ if(str[i]=='1') c++; } for(int i=0;i<N-1;i++){ if(str[i]==str[i+1] && str[i]=='1'){ cout << 2 << endl; return; } } if(c==0) cout << 0 << endl; else cout << 1 << endl; } int main() { int t; cin >> t; while (t--) { mainSolve(); } return 0; }