#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

static const double EPS = 1e-8;
static const double PI = 4.0 * atan(1.0);
static const double PI2 = 8.0 * atan(1.0);

#define REP(i,n)	for(int i=0;i<(int)n;++i)
#define ALL(c)		(c).begin(),(c).end()
#define CLEAR(v)	memset(v,0,sizeof(v))
#define MP(a,b)		make_pair((a),(b))
#define ABS(a)		((a)>0?(a):-(a))
#define FOR(i,s,n)	for(int i=s;i<(int)n;++i)

int main(int argc, char **argv) {
	int rgb[3], temp[3], c;
	REP(i, 3) cin >> rgb[i];
	sort(rgb, rgb + 3);
	for (int i = 10000000; i >= 0; --i) {
		REP(j, 3) temp[j] = rgb[j];
		if (temp[2] < i) continue;
		temp[2] -= i;
		c = max(0, min(temp[2] / 2, i - temp[1]));
		temp[2] -= c * 2; temp[1] += c;
		if (temp[1] < i) continue;
		temp[1] -= i;
		c = max(0, min(temp[2] / 2, i - temp[0]));
		temp[2] -= c * 2; temp[0] += c;
		c = max(0, min(temp[1] / 2, i - temp[0]));
		temp[1] -= c * 2; temp[0] += c;
		if (temp[0] < i) continue;
		cout << i << endl;
		break;
	}
	return 0;
}