/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author champon
 */

#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
#define se cout << "test ok" << endl;
#define sp << " " <<
#define enl "\n"
using namespace std;
using ll=long long;
using ld=long double;
using vi = vector<int>;
using vii = vector<vector<int>>;
using vl = vector<ll>;
using vll = vector<vector<ll>>;
using vlll = vector<vector<vector<ll>>>;
using vc = vector<char>;
using vcc = vector<vector<char>>;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
ll mod = ll(1e9)+7;
ll inf = ll(1e18);
void bl(bool b, ostream& out=cout){ out << (b ? "Yes" : "No") << endl; }
void bl2(bool b, ostream& out=cout){ out << (b ? "YES" : "NO") << endl; }
template<typename T> inline bool chmax(T &a, T b){ if(a<b){a=b; return true;} return false; }
template<typename T> inline bool chmin(T &a, T b){ if(a>b){a=b; return true;} return false; }
int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};

#ifndef INCLUDE_DEBUG_HPP
#define INCLUDE_DEBUG_HPP

#include <iostream>
#include <vector>
#include <map>
using namespace std;

namespace dbg {
    using ll = long long;

    class Debug {
    public:
        Debug(){}
        template<typename T>
        void vd(vector<T> vec);
        template<typename T>
        void vd2(vector<vector<T>> vec);
        template<typename T>
        void ad(T *arr, ll n);
        template<typename T, size_t N>
        void ad2(T (&arr)[N], ll n);
        template<typename T>
        void md(T mp);
    };

    template<typename T>
    void Debug::vd(vector<T> vec) {
        for (auto vv : vec) cout << vv << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::vd2(vector<vector<T>> vec) {
        for (auto vv : vec) {
            for (auto vvv : vv) cout << vvv << " ";
            cout << endl;
        }
    }

    template<typename T>
    void Debug::ad(T *arr, ll n) {
        for (int i = 0; i <= n; i++) cout << arr[i] << " ";
        cout << endl;
    }

    template<typename T, size_t N>
    void Debug::ad2(T (&arr)[N], ll n) {
        for (int i = 0; i <= N; i++) for (int j = 0; j <= n; j++) cout << arr[i][j] << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::md(T mp) {
        cout << "key : value" << endl;
        for (auto const &m : mp) cout << m.first << " : " << m.second << endl;
        cout << endl;
    }

}

#endif //INCLUDE_DEBUG_HPP

using dbg::Debug;
Debug debug;

class DRestoringRoadNetwork {
public:
	void solve(std::istream& in, std::ostream& out) {
	    int n;
	    in >> n;
	    vll a(n, vl(n));
	    vll dist(n, vl(n, inf));
	    for(int i=0; i<n; i++){
	        dist[i][i] = 0;
	    }
	    for(int i=0; i<n; i++){
	        for(int j=0; j<n; j++){
	            in >> a[i][j];
	            dist[i][j] = a[i][j];
	        }
	    }

        for(int k=0; k<n; k++){
            for(int i=0; i<n; i++){
                for(int j=0; j<n; j++){
                    chmin(dist[i][j], dist[i][k] + dist[k][j]);
                }
            }
        }

        ll res = 0;
        map<pair<int, int>, int> mp;
        for(int i=0; i<n; i++){
            for(int j=0; j<n; j++){
                if(a[i][j] != dist[i][j]){
                    out << -1 << enl;
                    return;
                }
                bool flg = true;
                for(int k=0; k<n; k++){
                    if(i == k || j == k) continue;
                    if(dist[i][j] == dist[i][k] + dist[k][j]) flg = false;
                }
                if(flg) {
                    res += dist[i][j];
                }
            }
        }

//        for(int i=0; i<n; i++){
//            for(int j=0; j<n; j++){
//                cout << dist[i][j] << " ";
//            }
//            cout << enl;
//        }

        out << res/2 << enl;
	}
};


int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
	DRestoringRoadNetwork solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}


Measured memory_bytes: 1664