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


#define ll long long int


int main(){
    int x,y,z;
    cin>>x>>y>>z;
    if((x+y)%2==0) cout<<z;
    else if((y+z)%2==0) cout<<x;
    else if((x+z)%2==0) cout<<y;
}