#include "bits/stdc++.h"
using namespace std;
#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define print(x) cout << x << "\n"
#define SORT(a, n) sort(a, a+n);

int main() {
    fastcin;
    int c[3], ans, q, r, n;
    cin >> c[0] >> c[1] >> c[2];
    SORT(c, 3);
    if(c[2]-c[1]>=(c[1]-c[0])*2) {
        c[2] -= (c[1]-c[0])*2;
        c[0] = c[1];
        ans = c[0] + (c[2]-c[0])/5;
    } else {
        c[0] += (c[2]-c[1])/2;
        c[2] = c[1] + (c[2]-c[1])%2;
        ans = c[0];
        if(c[1]-c[0]>2) {
            int tmp = (c[1]-c[0])/2;
            ans += tmp;
            if(tmp&1 && c[1]==c[2]) ans--;
        }
    }
    print(ans);
    return 0;
}