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

#define ll long long
#define endl '\n'

void Try() {
	int a, b, c; cin >> a >> b >> c;
	if (a % 2 == b % 2) cout << c << endl;
	else if (a % 2 == c % 2) cout << b << endl;
	else cout << a << endl;
    
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0);

    int t = 1;
    //cin >> t;
    for (int i = 1; i <= t; i++) {
        Try();
    }

}