#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <cctype>
#include <tuple>
#include <climits>
#include <bitset>
#include <cassert>
#include <random>

#ifdef _MSC_VER
#include <agents.h>
#endif

#define FOR(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define REV(v) v.rbegin(), v.rend()
#define MEMSET(v, s) memset(v, s, sizeof(v))
#define UNIQUE(v) (v).erase(unique(ALL(v)), (v).end())
#define MP make_pair
#define MT make_tuple

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const int N = 10;
int G[N][N];

int main(){
	int cnt[3];
	rep(i, 3) cin >> cnt[i];

	int ans = *min_element(cnt, cnt + 3);
	rep(i, 3) cnt[i] -= ans;

	int *M;
	while (*(M = max_element(cnt, cnt + 3)) > 1){		
		int *m = min_element(cnt, cnt + 3);
		*M -= 2, *m += 1;
		int tmp = *min_element(cnt, cnt + 3);
		rep(i, 3) cnt[i] -= tmp;
		ans += tmp;
	}
	cout << ans << endl;

	return 0;
}