#include<bits/stdc++.h>
main(){
    int N[3];
    scanf("%d%d%d",&N[0],&N[1],&N[2]);
    int count = 0;
    std::sort(N,N+3);
    while(N[0]>=1 || N[2] >= 3){
        int num = N[0];
        N[0] -= num;
        N[1] -= num;
        N[2] -= num;
        count += num;
        N[0] = N[2]/4 + N[2]%2;
        N[2] -= N[0]*2;
        std::sort(N,N+3);
    }
    printf("%d\n",count);
}