#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>

using namespace std;

#define ll long long
#define ld long double
#define EPS 0.0000000001
#define INF 1e9
#define LINF (ll)INF*INF
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,a,n) for(int i=a;i<(n);i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)

#define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int,int> pii;
typedef vector<pii> vp;

int gcd(int a, int b){
    if(b==0) return a;
    return gcd(b,a%b);
}
int lcm(int a, int b){
    return a/gcd(a,b)*b;
}


signed main(void) {
    vi a(3);
    rep(i,3)cin >> a[i];
    sort(all(a));
    int ans = a[0];
    a[2] -= a[0];
    a[1] -= a[0];
    a[0] -= a[0];
    while(1){
        if(a[2] >= 2 && a[0] == 0){
            a[2] -= 2;
            a[0]++;
        }
        if(a[2] >= 2 && a[1] == 0){
            a[2] -= 2;
            a[1]++;
        }
        //cout << a[0] << " " << a[1] << " " << a[2] << endl;
        if(a[0] > 0 && a[1] > 0 && a[2] > 0){
            a[0]--;
            a[1]--;
            a[2]--;
            ans++;
        }else{
            break;
        }
        sort(all(a));
    }
    cout << ans << endl;
}