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

int main() {
    ll R, G, B;
    cin >> R >> G >> B;

    auto ok = [&](ll k) -> bool {
        ll sr = max(0LL, R - k), sg = max(0LL, G - k), sb = max(0LL, B - k);
        ll dr = max(0LL, k - R), dg = max(0LL, k - G), db = max(0LL, k - B);

        ll cr = sr / 2, cg = sg / 2, cb = sb / 2;

        if (dr > cg + cb) return false;
        if (dg > cr + cb) return false;
        if (db > cr + cg) return false;
        if (dr + dg + db > cr + cg + cb) return false;
        return true;
    };

    ll lo = 0, hi = (R + G + B) / 3 + 1; // 最大でも総数/3
    while (lo + 1 < hi) {
        ll mid = (lo + hi) / 2;
        if (ok(mid)) lo = mid;
        else hi = mid;
    }
    cout << lo << "\n";
}