#include <stdio.h>

void main(void){
    int a,b,c;
    scanf("%d %d %d",&a,&b,&c);
    int purple = 0,shortage = 0;
    if(a ==b){
        purple = a + c/2;
    }else{
        if(a < b){
            purple = a;
            shortage = b-a;
        }else{
            purple = b;
            shortage = a-b;
        }
        if(c <= shortage){
            purple += c;
        }else{
            //c > shortage
            c -= shortage;
            purple += shortage + c/2;
        }
    }

    printf("%d",purple);
}