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

void scan(T...)(ref T args) {
    auto line = readln.split;
    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);
        }
    }
}

bool chmin(T, U...)(ref T x, U args) {
    bool isChanged;
    foreach (arg; args) if (x > arg) {
        x = arg;
        isChanged = true;
    }
    return isChanged;
}

bool chmax(T, U...)(ref T x, U args) {
    bool isChanged;
    foreach (arg; args) if (x < arg) {
        x = arg;
        isChanged = true;
    }
    return isChanged;
}


enum inf = 1_001_001_001;
enum infl = 1_001_001_001_001_001_001L;


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

    foreach (k ; 0 .. N) {
        foreach (i ; 0 .. N) {
            foreach (j ; i + 1 .. N) {
                if (a[i][j] > a[i][k] + a[k][j]) {
                    writeln(-1);
                    return;
                }
            }
        }
    }

    long ans;

    foreach (i ; 0 .. N) {
        foreach (j ; i + 1 .. N) {
            bool used = true;
            foreach (k ; 0 .. N) {
                if (k == i || k == j) continue;
                if (a[i][j] == a[i][k] + a[k][j]) {
                    used = false;
                    break;
                }
            }
            if (used) ans += a[i][j];
        }
    }

    writeln(ans);
}
