#include <stdio.h>

int main() {
    int N_1;
    int N_2;
    int N_3;
    int Suma;
    int Prom;
    scanf("%d",& N_1);
    scanf("%d",& N_2);
    scanf("%d",& N_3);
    Suma= N_1+N_2+N_3;
    Prom= Suma/3;
        printf("Prom=%d\n",Prom);
    return 0;
}