#include<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cstring>
using namespace std;

typedef long long LL;
typedef vector<int> VI;

#define REP(i,n) for(int i=0; i<int(n); i++)
#define EACH(i,c) for(__typeof((c).begin()) i=(c).begin();i!=(c).end();i++)

int R, G, B;
int main() {
    scanf("%d%d%d", &R, &G, &B);
    int A = min(R, min(G, B));
    R -= A; G -= A; B -= A;

    int lo = 0, hi = 1e9;
    while (hi-lo > 1) {
	int m = (lo + hi) / 2;
	int f = max(0, R-m)/2 + max(0, G-m)/2 + max(0, B-m)/2;
	int z = max(0, m-R) + max(0, m-G) + max(0, m-B);
	if (z <= f) lo = m;
	else hi = m;
    }

    printf("%d\n", A + lo);
    
    return 0;
}