/*
 *   Copyright (c) 2025 Emon Thakur
 *   All rights reserved.
 */
#include<bits/stdc++.h>
using namespace std;
int main()
{
    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 if(b%2==c%2) cout<<a<<endl;
}