#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){
        shortage = a - b ;
        purple = b;
    }else if( b > a ){
        shortage = b - a ;
        purple = a;
    }

    c -= shortage;
    if(c <= 1){
        c = 0;
    }
    purple += c/2;
    if(shortage < 0){
        shortage = 0;
    }
    purple += shortage;
    printf("%d",purple);

}