import std.stdio, std.string, std.conv;
import std.range, std.algorithm, std.array, std.typecons, std.container;
import std.math, std.numeric, core.bitop;

enum inf3 = 1_001_001_001;
enum inf6 = 1_001_001_001_001_001_001L;
enum mod = 1_000_000_007L;


void main() {
    int n;
    scan(n);
    auto a = iota(n).map!(i => readln.split.to!(long[])).array;

    debug {
        //writeln(a);
    }

    auto score = new long[](1 << n);

    foreach (s ; 1 .. 1 << n) {
        foreach (j ; 0 .. n) {
            if (s & (1 << j)) {
                score[s] = score[s ^ (1 << j)];
                foreach (i ; 0 .. n) {
                    if (s & (1 << i)) {
                        score[s] += a[i][j];
                    }
                }
                break;
            }
        }
    }

    debug {
        writeln(score);
    }

    auto dp = new long[](1 << n);

    foreach (s ; 1 .. 1 << n) {
        for (int t = s; t > 0; t = (t - 1) & s) {
            dp[s] = max(dp[s], dp[s ^ t] + score[t]);
        }
    }

    auto ans = dp[(1 << n) - 1];

    writeln(ans);
}







void scan(T...)(ref T args) {
    import std.stdio : readln;
    import std.algorithm : splitter;
    import std.conv : to;
    import std.range.primitives;

    auto line = readln().splitter();
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}

void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}
