using System;
using System.Linq;
using System.Collections.Generic;

namespace Contest
{
    class Program
    {
        static void Main(string[] args)
        {
            ARC083.D();
        }
        class ARC083
        {
            public static void C()
            {
                var A = Read.Int();
                var B = Read.Int();
                var C = Read.Int();
                var D = Read.Int();
                var E = Read.Int();
                var F = Read.Int();
                var hashAB = new HashSet<int>();
                for (int a = 0; a * A * 100 <= F; ++a)
                {
                    for (int b = 0; b * B * 100 <= F; ++b)
                    {
                        var v = (a * A + b * B) * 100;
                        if(!hashAB.Contains(v) && v>0 && v <= F)
                        {
                            hashAB.Add(v);
                        }
                    }
                }
                var hashCD = new HashSet<int>();
                for (int c = 0; c * C <= F; ++c)
                {
                    for (int d = 0; d * D <= F; ++d)
                    {
                        var v = (c * C + d * D);
                        if (!hashCD.Contains(v) && v <= F)
                        {
                            hashCD.Add(v);
                        }
                    }
                }
                double max = -1;
                int maxAB = 0, maxCD = 0;
                foreach(var water in hashAB)
                {
                    foreach(var suger in hashCD)
                    {
                        if (water / 100 * E < suger) { continue; }
                        if (water + suger > F) { continue; }
                        var node = 1.0 * suger / (water + suger);
                        if (node > max)
                        {
                            max = node;
                            maxAB = water;
                            maxCD = suger;
                        }
                    }
                }
                Console.WriteLine("{0} {1}", maxAB + maxCD, maxCD);
            }
            public static void D()
            {
                var N = Read.Int();
                var A = Read.LongMatrix(N, N);
                var Dist = Util.Dup(A);
                Util.WarshallFloyd(Dist);
                for(int i = 0; i < N; ++i)
                {
                    for(int j = 0; j < N; ++j)
                    {
                        if (Dist[i, j] < A[i, j]) { Console.WriteLine(-1); return; }
                    }
                }
                long total = 0;
                for(int i = 0; i < N; ++i)
                {
                    for(int j = i + 1; j < N; ++j)
                    {
                        bool hasAnotherPath = false;
                        for (int k = 0; k < N; ++k)
                        {
                            if (i != k && j != k && Dist[i, k] + Dist[k, j] == Dist[i, j]) { hasAnotherPath = true; break; }
                        }
                        if (!hasAnotherPath) { total += Dist[i, j]; }
                    }
                }
                Console.WriteLine(total);
            }
        }

        class Util
        {
            public static long[] ASum(long[] array)
            {
                var res = new long[array.Length + 1];
                for (int i = 0; i < array.Length; ++i)
                {
                    res[i + 1] = res[i] + array[i];
                }
                return res;
            }
            public static T[,] Dup<T>(T[,] matrix)
            {
                var n0 = matrix.GetLength(0);
                var n1 = matrix.GetLength(1);
                var m = new T[n0, n1];
                for (int i = 0; i < n0; ++i)
                {
                    for (int j = 0; j < n1; ++j)
                    {
                        m[i, j] = matrix[i, j];
                    }
                }
                return m;
            }
            public static void WarshallFloyd(long[,] dist)
            {
                var N = dist.GetLength(0);
                for (int k = 0; k < N; ++k)
                {
                    for (int i = 0; i < N; ++i)
                    {
                        for (int j = 0; j < N; ++j)
                        {
                            dist[i, j] = Math.Min(dist[i, j], dist[i, k] + dist[k, j]);
                        }
                    }
                }
            }
        }

        static class Read
        {
            static Queue<string> queue = new Queue<string>();
            static void Enqueue() { var ss = Console.ReadLine().Split(' '); foreach (var s in ss) { queue.Enqueue(s); } }
            public static int Int() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt32(queue.Dequeue()); }
            public static long Long() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt64(queue.Dequeue()); }
            public static string Str() { if (queue.Count == 0) { Enqueue(); } return queue.Dequeue(); }
            public static int[] IntN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray(); }
            public static long[] LongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray(); }
            public static string[] StrN() { return Console.ReadLine().Split(' '); }
            public static Tuple<int, int>[] TupleInt(int n) { List<Tuple<int, int>> list = new List<Tuple<int, int>>(); for (int i = 0; i < n; ++i) { var ab = Read.IntN(); list.Add(new Tuple<int, int>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<long, long>[] TupleLong(int n) { List<Tuple<long, long>> list = new List<Tuple<long, long>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<long, long>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<string, string>[] TupleStr(int n) { List<Tuple<string, string>> list = new List<Tuple<string, string>>(); for (int i = 0; i < n; ++i) { var ab = Read.StrN(); list.Add(new Tuple<string, string>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<double, double>[] TupleDouble(int n) { List<Tuple<double, double>> list = new List<Tuple<double, double>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<double, double>(ab[0], ab[1])); } return list.ToArray(); }
            public static long[,] LongMatrix(int r, int c)
            {
                var mat = new long[r, c];
                for (int i = 0; i < r; ++i)
                {
                    var x = Read.LongN();
                    for (int j = 0; j < c; ++j)
                    {
                        mat[i, j] = x[j];
                    }
                }
                return mat;
            }
            public static Dictionary<int, HashSet<int>> AdjacencyList(int N, int M, bool isDirectional = false)
            {
                Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
                for (int i = 0; i <= N; ++i) { dict.Add(i, new HashSet<int>()); }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN(); dict[ab[0]].Add(ab[1]);
                    if (!isDirectional) { dict[ab[1]].Add(ab[0]); }
                }
                return dict;
            }
            public static Dictionary<int, Dictionary<int, long>> AdjacencyListWithWeight(int N, int M)
            {
                Dictionary<int, Dictionary<int, long>> dict = new Dictionary<int, Dictionary<int, long>>();
                for (int i = 0; i <= N; ++i)
                {
                    dict.Add(i, new Dictionary<int, long>());
                }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN();
                    dict[ab[0]].Add(ab[1], ab[2]);
                    dict[ab[1]].Add(ab[0], ab[2]);
                }
                return dict;
            }
        }
    }
}


Measured memory_bytes: 22488