#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

int main(){
  ios::sync_with_stdio(false);
  int T;
  cin >> T;
  rep(t,T){
    string S;
    cin >> S;
    vector<int> v;
    rep(i,S.length()){
      v.push_back((int)(S[i]-'0'));
    }
    
    while(v.size()>1){
      vector<int> tmp;
      rep(i,v.size()-1){
        int a = v[i]+v[i+1];
        if(a>=10) a = 1 + (a%10);
        tmp.push_back(a);
      }
      v = tmp;
    }
    
    cout << v[0] << endl;
  }
  return 0;
}