#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define xprintf(fmt,...) fprintf(stderr,fmt,__VA_ARGS__)
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;cnt<(l);++cnt)
#define iterate(cnt,b,e) for(auto cnt=(b);cnt!=(e);++cnt)
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
#define EPS 1e-12
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename iterator> inline size_t argmin(iterator begin, iterator end) { return distance(begin, min_element(begin, end)); }
template<typename iterator> inline size_t argmax(iterator begin, iterator end) { return distance(begin, max_element(begin, end)); }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }

mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        inline MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) {
            for (auto it = begin; it != end; ++it) *this >> *it;
        }
    };
}
MaiScanner scanner;


class Graph2d {
public:
    typedef int numeric;
    size_t n;
    vector<numeric> matrix;

    Graph2d(size_t size) :n(size), matrix(size*size) {};

    void resize(size_t s) {
        n = s;
        matrix.resize(n*n);
    }

    inline numeric& at(int y, int x) { return matrix[y*n + x]; }
    inline numeric& operator()(int y, int x) { return matrix[y*n + x]; }
    inline numeric at(int y, int x) const { return matrix[y*n + x]; }
    inline numeric operator()(int y, int x) const { return matrix[y*n + x]; }

    inline void connect(int u, int v, int dist = 1) {
        at(u, v) = at(v, u) = dist;
    }
    inline void connect_d(int from, int to, int dist = 1) { // directedEdge u->v
        at(from, to) = dist;
    }
};


ll field[333][333];
int flg[333][333];

ll m, n, kei;


void warshall_floyd(Graph2d& g) {
    int i, j, k;
    for (i = 0; i < g.n; i++) {
        for (j = 0; j < g.n; j++) {
            for (k = 0; k < g.n; k++) {
                g(j, k) = min(g(j, k), g(j, i) + g(i, k));
            }
        }
    }
}




int main() {
    scanner >> n;

    ll sum = 0;
    repeat(y, n) {
        repeat(x, n) {
            ll a = 0;
            scanner >> a;
            field[y][x] = a;
            //sum += a;
        }
    }

    {
        int i, j, k;
        for (i = 0; i < n; i++) {
            for (j = 0; j < n; j++) {
                for (k = 0; k < n; k++) {
                    if (field[j][k] > field[j][i] + field[i][k]){
                        cout << -1 << endl;
                        return 0;
                    }
                }
            }
        }
                    
        for (i = 0; i < n; i++) {
            for (j = 0; j < n; j++) {
                for (k = 0; k < n; k++) {
                    if (j != i && i != k && j != k && field[j][k] == field[j][i] + field[i][k]) {
                        //printf("%d %d %d : %d\n",j,i,k,field[j][k]);
                        //sum -= field[j][k];
                        flg[j][k] = flg[k][j] = true;
                        // field[j][k] = 0;
                        // field[j][i] = 0;
                        // field[i][k] = 0;
                    }
                }
            }
        }
    }
    
    repeat(i,n){
        repeat(j,n){
            if (!flg[i][j])
                sum += field[i][j];
        }
    }
    
    // debugaa(field,n,n);
    cout << sum/2 << endl;

    return 0;
}

Measured memory_bytes: 1408