#include <bits/stdc++.h>
#ifdef __LOCAL
    #define DBG(X) cout << #X << " = " << (X) << endl;
    #define SAY(X) cout << (X) << endl;
    #include <filesystem>
    namespace fs = std::filesystem;
#else
    #define DBG(X)
    #define SAY(X)
#endif

using namespace std;

using ll = long long int;
using ull = unsigned long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

int dx[]={1, 0, -1, 0, 1,-1, 1,-1};
int dy[]={0, 1, 0, -1, 1, 1,-1,-1};
const int INT_INF = (int)(2e9);
const ll  LL_INF = (ll)(2e18);
static mt19937 _g(time(nullptr));
 
inline ll randint(ll a, ll b) { ll w = (_g() << 31LL) ^ _g(); return a + w % (b - a + 1); }
inline void fast_io() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); };
template<typename T, typename S> inline ostream& operator<<(ostream& os, const pair<T, S> p) { cout << "[" << p.first << ";" << p.second << "]"; return os; }
template<typename T, typename S> inline ostream& operator<<(ostream& os, const map<T, S> p) { for (auto el : p) cout << "[" << el.first << ";" << el.second << "]"; return os; }
template<typename T> inline ostream& operator<<(ostream& os, const vector<T>& v) { for (auto el : v) cout << el << " "; return os; }
template<typename T> inline vector<T> fetch_vec(int sz) { vector<T> ret(sz); for (auto& elem : ret) cin >> elem; return ret; }

int N;
vector<vector<ll>> A;
void input(){
    fast_io();
    #ifdef __LOCAL
        fs::path __p = __FILE__;
        fs::path __input, __output;
        __input = __output = __p.parent_path();
        __input += string("/input/") + string(__p.stem()) + string(".txt");
        __output += string("/output/") + string(__p.stem()) + string(".txt");
        freopen(__input.c_str(), "r", stdin);
        freopen(__output.c_str(), "w", stdout);
    #endif
    cin >> N;
    A.assign(N,vector<ll>(N,0));
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            cin >> A[i][j];
}

int prim(int s=0){
    priority_queue<pii,vector<pii>,greater<pii> > pq;
    pq.emplace(0,s);
    int total=0;
    vector<bool> used(N,false);
    while(!pq.empty()){
        int d;
        int cur;
        tie(d,cur) = pq.top();
        pq.pop();
        if(used[cur]) continue;
        used[cur] = true;
        total += d;
        for (int i = 0; i < N; i++)
        {
            if(i==cur) continue;
            if(used[i]) continue;
            pq.emplace(A[cur][i],i);
        }
        
    }
    return total;
}

int solve(){
    auto D = A;
    ll ans=0;
    vector<vector<bool>> used(N,vector<bool>(N,true));
    for (int k = 0; k < N; k++)
    {
        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < N; j++)
            {
                if(i==k || j==k) continue;
                if(D[i][j]==(D[i][k]+D[k][j])) used[i][j]=false;
                else if(D[i][j]<D[i][k]+D[k][j]) continue;
                else {cout << -1 << endl; return 0;}
                // D[i][j] = min(D[i][j],D[i][k]+D[k][j]);
            }
            
        }
        
    }
    DBG(used)
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if(used[i][j]) ans+=A[i][j];
        }
        
    }
    
    // if(A!=D){
    //     cout << -1 << endl;
    //     return 0;
    // }
    // cout << prim() << endl;
    cout << ans/2 << endl;    
    return 0;
}   

int main()
{
    input();
    solve();
    return 0;
}


Measured memory_bytes: 1664