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

typedef long long ll;
typedef double dl;

#define endl "\n"
#define vi vector<int>
#define mii map<int,int>
#define mci map<char,int>
#define optimize() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define fraction() cout.unsetf(ios::floatfield); cout.precision(10); cout.setf(ios::fixed,ios::floatfield);
#define yes cout<<"YES"<<endl;
#define no cout<<"NO"<<endl;

void solve(){
    int n, k, j;
    cin >> n >> k >> j;

    if((n % 2) == (k % 2)){
        cout << j << endl;
    }
    else if((n % 2) == (j % 2)){
        cout << k << endl;
    }else{
        cout << n << endl;
    }
    //cout << n-k<< endl;

}

int main()
{
    optimize();

    int t=1;
    //cin >> t;

    while(t--)  solve();

    return 0;
}