#include <bits/stdc++.h>
using namespace std;

template<typename T>
istream &operator>>(istream &is,vector<T> &a){
    for(auto &v : a) cin >> v;
    return is;
}
template<typename T>
ostream &operator<<(ostream &os,const vector<T> &a){
    if(a.size() == 0) return os;
    cout << a.at(0);
    for(int i=1; i<a.size(); i++) cout << " " << a.at(i);
    cout << "\n";
    return os;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int R,G,B; cin >> R >> G >> B;
    int low = 0,high = 10010010;
    while(high-low > 1){
        int mid = (high+low)/2;
        int over = 0;
        if(R >= mid) over += (R-mid)/2;
        else over += R-mid;
        if(G >= mid) over += (G-mid)/2;
        else over += G-mid;
        if(B >= mid) over += (B-mid)/2;
        else over += B-mid;

        if(over >= 0) low = mid;
        else high = mid;
    }
    cout << low << endl;
}