#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
    int r, g, b;
    while (cin>>r>>g>>b) {
        int res=min({r, g, b}), prev=res;
        while (true) {
            auto x=minmax({r, g, b});
            int s=r+g+b;
            r=x.first, b=x.second, g=s-(r+b);
            if (b>=2) { b-=2; r++; }
            res=min({r, g, b});
            if (res<=prev) { res=prev; break; }
            prev=res;
        }
        cout<<res<<endl;
    }
}