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

typedef long long ll;

#define pb      push_back
#define debug   cout<<"check"<<endl;cout.flush();
#define all(x)  (x).begin(),(x).end()
#define endl    '\n'

const ll N=200005;
const ll mod=1000000007;
const ll INF=2e18L+5;

void solve(){
    ll 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::sync_with_stdio(false);cin.tie(nullptr);
    
    int t=1;
    //cin>>t;
    for(int i=1;i<=t;i++){
        solve();
    }
    
    return 0;
}