Baekjoon #1507

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        FastReader rd = new FastReader();
        int N = rd.nextInt();

        int[][] a1 = new int[N][N];
        int[][] a2 = new int[N][N];

        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                a1[i][j] = rd.nextInt();
                a2[i][j] = a1[i][j];
            }
        }

        for (int k = 0; k < N; k++) {
            for (int i = 0; i < N; i++) {
                for (int j = 0; j < N; j++) {
                    if (i == j || j == k || k == i) continue;

                    if (a1[i][j] > a1[i][k] + a1[k][j]) {
                        System.out.println(-1);
                        return;
                    }

                    if (a1[i][j] == a1[i][k] + a1[k][j]) {
                        a2[i][j] = 0;
                    }
                }
            }
        }

        int sum = 0;
        for (int i = 0; i < N; i++) {
            for (int j = i + 1; j < N; j++) {
                sum += a2[i][j];
            }
        }
        System.out.println(sum);
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}