#![allow(unused, non_snake_case, dead_code, non_upper_case_globals)]
use std::cmp::*;
use std::collections::*;
use std::mem::*;

fn main() {
    let (r, w, e) = (std::io::stdin(), std::io::stdout(), std::io::stderr());
    let mut io = IO::new(r.lock(), w.lock(), e.lock());
    let n = io.read::<usize>();
    let a = io.readmat::<i64>(n, n);
    // n^3
    let mut dists = vec![vec![INF; n]; n];

    for i in 0..n {
        for j in 0..n {
            dists[i][j] = min(dists[i][j], a[i][j]);
        }
    }

    let mut dp = dists.clone();

    for k in 0..n {
        for i in 0..n {
            for j in 0..n {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k][j]);
            }
        }
    }
    let mut ok = true;
    for i in 0..n {
        for j in 0..n {
            if a[i][j] != dp[i][j] {
                io.writeln(-1);
                ok = false;
                return;
            }
        }
    }
    let mut ans = 0;
    // for i in 0..n {
    //     for j in i + 1..n {
    //         if dp[i][j] == a[i][j] {
    //             ans += dp[i][j];
    //         }
    //     }
    // }

    // let mut e = vec![vec![0; n]; n];
    let mut e = a.clone();
    for k in 0..n {
        for i in 0..n {
            if k == i {
                continue;
            }
            for j in 0..n {
                if k == j {
                    continue;
                }
                if a[i][k] + a[k][j] == a[i][j] {
                    e[i][j] = 0;
                }
            }
        }
    }
    for c in e.iter() {
        for x in c.iter() {
            ans += x;
        }
    }
    io.writeln(ans / 2);
}

static MX: usize = 1010101;
static MOD: i64 = 1000000007;
static INF: i64 = std::i64::MAX >> 1;
// IO
use std::io::*;
struct IO<R: Read, W: Write, E: Write> {
    Read: R,
    Write: BufWriter<W>,
    Error: BufWriter<E>,
}
impl<R: Read, W: Write, E: Write> IO<R, W, E> {
    fn new(r: R, w: W, e: E) -> IO<R, W, E> {
        IO {
            Read: r,
            Write: BufWriter::new(w),
            Error: BufWriter::new(e),
        }
    }
    fn read<T>(&mut self) -> T
    where
        T: std::str::FromStr,
    {
        let next: String = self
            .Read
            .by_ref()
            .bytes()
            .map(|c| c.unwrap() as char)
            .skip_while(|c| c.is_whitespace())
            .take_while(|c| !c.is_whitespace())
            .collect();
        next.parse().ok().unwrap()
    }
    fn chars(&mut self) -> Vec<char> {
        self.read::<String>().chars().collect()
    }
    fn chari(&mut self) -> Vec<i64> {
        self.chars()
            .iter()
            .map(|&c| (c as u8 - b'0') as i64)
            .collect::<Vec<i64>>()
    }
    fn readn<T: std::str::FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.read::<T>()).collect::<Vec<_>>()
    }
    fn readmat<T: std::str::FromStr>(&mut self, n: usize, m: usize) -> Vec<Vec<T>> {
        (0..n).map(|_| self.readn(m)).collect()
    }
    fn write<S: ToString>(&mut self, val: S) {
        self.Write.write(val.to_string().as_bytes());
    }
    fn writeln<S: ToString>(&mut self, val: S) {
        self.Write.write(val.to_string().as_bytes());
        self.Write.write(b"\n");
    }
    fn debug<S: std::fmt::Debug>(&mut self, val: S) {
        writeln!(self.Error, "(debug) {:?}", &val);
    }
    fn debug2<S: std::fmt::Debug, T: std::fmt::Debug>(&mut self, val1: S, val2: T) {
        writeln!(self.Error, "(debug2) {:?} -> {:?}", val1, val2);
    }
    fn debug3<S: std::fmt::Debug, T: std::fmt::Debug, U: std::fmt::Debug>(
        &mut self,
        val1: S,
        val2: T,
        val3: U,
    ) {
        writeln!(
            self.Error,
            "(debug3) {:?} -> {:?} -> {:?}",
            val1, val2, val3
        );
    }
}


Measured memory_bytes: 4932