import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

int calc(int r, int g, int b) {

    // n 個のアクセサリーが作れるか
    bool canMake(int n) {
        int k = 0;
        foreach (x; [r - n, g - n, b - n]) {
            k += x >= 0
                ? x / 2 // 2 個単位で他の石に交換できる
                : x;    // x だけ足りない
        }
        return k >= 0;
    }

    int ans = 0;
    int lo = 0;
    int hi = max(r, g, b);
    while (lo <= hi) {
        int m = (lo + hi) / 2;
        if (canMake(m)) {
            ans = max(ans, m);
            lo = m + 1;
        }
        else {
            hi = m - 1;
        }
    }
    return ans;
}

void main() {
    auto rgb = readints;
    auto ans = calc(rgb[0], rgb[1], rgb[2]);
    writeln(ans);
}