#include<stdio.h>

int main() {

    int x, y, z, parity;
    scanf("%d %d %d", &x, &y, &z);

    if (x%2==0 && y%2==0 || x%2!=0 && y%2!=0){
        parity = z;
    }
    else if (z%2==0 && y%2==0 || z%2!=0 && y%2!=0){
        parity = x;
    }

    else {
        parity=y;
    }

    printf("%d", parity);



}