#include<algorithm>
#include<complex>
#include<ctype.h>
#include<iomanip>
#include<iostream>
#include<fstream>
#include<map>
#include<math.h>
#include<numeric>
#include<queue>
#include<set>
#include<stack>
#include<stdio.h>
#include<string>
#include<string>
#include<vector>

using namespace std;
typedef long long ll;

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

template < typename T >
void vprint(T &V){
	for(auto v : V){
    	cout << v << " ";
	}
	cout << endl;
}

// 追加で何個作れるか
ll f(ll r, ll g){
    ll num = 0;
    while(true){
        if(r>g){
            swap(r, g);
        }

        if(g<3){
            break;
        }

        if(r==0){
            g -= 2;
            r++;
        }
        else{
            g -= 2;

            // make
            g--;
            r--;
            num++;
        }
    }
    return num;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    vector<ll> A(3);
    FOR(i, 0, 3){
        cin >> A[i];
    }
    sort(ALL(A));

    ll num = A[0];

    ll r = A[1] - A[0];
    ll g = A[2] - A[0];
    
    ll add = f(r, g);
    
    p(num + add);
    
    return 0;
}