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

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define pb push_back
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

int main() {
	cin.tie(0)->sync_with_stdio(0);
    int a;
    for(int i = 0; i < 100; i++)
        cin >> a;
    a = a%10;
    if(a == 0)
        a = 10;
    cout << a << "\n";
}