#include<bits/stdc++.h>
#include<iostream>
#include<cmath>
#include<vector>
#include<string>
#include<queue>
#include<set>
#include<map>
#include<algorithm>
#include<functional>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll, int> plli;
typedef pair<int, pii> pipii;
typedef vector<vector<int> > mati;
typedef vector<vector<double> > matd;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vector<vector<bool>>> vvvb;

#define FOR(i,x,y) for(ll i=(ll)x; i<(ll)y; ++i)
#define REP(i,y) FOR(i, 0, y)
#define RFOR(i,x,y) for(ll i=(ll)x; i>=(ll)y; --i)
#define RREP(i,x) RFOR(i, x, 0)

template <typename T>
void vec_print(vector<T> VEC){
  REP(i, VEC.size()){
    cout << VEC[i] << " ";
  }
  cout << "\n";
};

template <typename T>
void mat_print(vector<vector<T> > MAT){
  REP(i, MAT.size()){
    REP(j, MAT[i].size()){
      cout << MAT[i][j] << " ";
    }
    cout << "\n";
  }
};

template <typename CLASS1, typename CLASS2>
class HOGE{
  public:
    CLASS1 key;
    CLASS2 value;
    HOGE(void){
      return;
    };
    HOGE(CLASS1 key, CLASS2 value){
      this->key = key;
      this->value = value;
    };
    ~HOGE(void){
      return;
    };

    void print(void){
      cout << "key : " << key << ", value : " << value << "\n";
      return;
    };
    
    bool operator==(const HOGE &obj){
      return (this->value == obj.value);
    };
    bool operator<(const HOGE &obj){
      return (this->value < obj.value);
    };
    bool operator>(const HOGE &obj){
      return (this->value > obj.value);
    };
};

constexpr int INF = (1<<30);
constexpr ll INFLL = 1LL<<62;
constexpr long double EPS = 1e-12;
constexpr ll MOD = (ll)((1E+9)+7);

int main(){
  cin.tie(0); // cut the cin and cout (default, std::flush is performed after std::cin)
  ios::sync_with_stdio(false); // cut the iostream and stdio (DON'T endl; BUT "\n";)

  ll N;
  cin >> N;
  vvll min_dist(N, vll(N, 0));
  REP(x, N){
    REP(y, N){
      cin >> min_dist[x][y];
    }
  }

  vll path;
  vector<HOGE<pair<ll, ll>, ll>> Hpath;
  REP(x, N){
    FOR(y, x+1, N){
      pair<ll, ll> pr(x, y);
      HOGE<pair<ll, ll>, ll> H_tmp(pr, min_dist[x][y]);
      Hpath.push_back(H_tmp);
    }
  }

  sort(Hpath.begin(), Hpath.end());

  vvll calc_map(N, vll(N, INFLL));

  REP(i, N) calc_map[i][i] = 0;

  REP(i, Hpath.size()){
    ll tmpx = Hpath[i].key.first;
    ll tmpy = Hpath[i].key.second;
    ll tmp_cost = Hpath[i].value;

    REP(tmpz, N){
      if(calc_map[tmpx][tmpz]!=INFLL && calc_map[tmpz][tmpy]!=INFLL){
        calc_map[tmpx][tmpy] = min(calc_map[tmpx][tmpy], calc_map[tmpx][tmpz] + calc_map[tmpz][tmpy]);
      }
    }
    calc_map[tmpy][tmpx] = calc_map[tmpx][tmpy];

    if(calc_map[tmpx][tmpy]<tmp_cost){
      cout << "-1" << "\n";
      return 0;
    }
    if(calc_map[tmpx][tmpy]==tmp_cost) continue;

    calc_map[tmpx][tmpy] = tmp_cost;
    calc_map[tmpy][tmpx] = tmp_cost;
    path.push_back(tmp_cost);
  }

  REP(x, N){
    REP(y, N){
      if(calc_map[x][y] != min_dist[x][y]){
        cout << "-1" << "\n";
        return 0;
      }
    }
  }

  ll ans = 0;
  REP(i, path.size()){
    ans += path[i];
  }

  cout << ans << "\n";

  return 0;
}


Measured memory_bytes: 2808