/**
 * Created at 07:10 on 2019-08-30
 */

import java.io.*;
import java.util.*;

public class Main {

  static FastScanner sc = new FastScanner();
  static Output out = new Output(System.out);

  static final int[] dx = {0, 1, 0, -1};
  static final int[] dy = {-1, 0, 1, 0};

  static final long MOD = (long) (1e9 + 7);
  static final long INF = Long.MAX_VALUE / 8;

  static final int e5 = (int) 1e5;

  public static class Solver {
    public Solver() {

      int N = sc.nextInt();

      long[][] cost = new long[N][N];

      for (int i=0; i<N; i++) {
        for (int j=0; j<N; j++) {
          cost[i][j] = sc.nextLong();
        }
      }

      for (int k=0; k<N; k++) {
        for (int i=0; i<N; i++) {
          for (int j=0; j<N; j++) {
            if (cost[i][j] > cost[i][k] + cost[k][j]) {
              out.println(-1);
              return;
            }
          }
        }
      }

      long[][] cost2 = new long[N][N];
      for (int i=0; i<N; i++) {
        for (int j=0; j<N; j++) {
          if (i == j) continue;
          cost2[i][j] = INF;
        }
      }

      PriorityQueue<Edge> es = new PriorityQueue<Edge>();
      for (int i=0; i<N; i++) {
        for (int j=i+1; j<N; j++) {
          es.add(new Edge(i, j, cost[i][j]));
        }
      }

      long ans = 0;
      while(!es.isEmpty()) {

        Edge e = es.remove();

        if (cost2[e.from][e.to] > e.cost) {
          ans += e.cost;
          cost2[e.from][e.to] = e.cost;
          cost2[e.to][e.from] = e.cost;
          for (int i=0; i<N; i++) {
            for (int j=0; j<N; j++) {
              cost2[i][j] = Math.min(cost2[i][j], cost2[i][e.from] + cost2[e.from][e.to] + cost2[e.to][j]);
              cost2[i][j] = Math.min(cost2[i][j], cost2[i][e.to] + cost2[e.to][e.from] + cost2[e.from][j]);
            }
          }
        }

      }

      out.println(ans);

    }

    class Edge implements Comparable<Edge> {
      int from, to;
      long cost;

      public Edge(int i, int j, long c) {
        from = i;
        to = j;
        cost = c;
      }

      public int compareTo(Edge e) {
        if (e.cost == cost) return 0;
        else return (cost - e.cost > 0) ? 1 : -1;
      }
    }
  }

  public static void main(String[] args) {
    new Solver();
    out.flush();
  }

  static class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
      if (ptr < buflen) {
        return true;
      } else {
        ptr = 0;
        try {
          buflen = in.read(buffer);
        } catch (IOException e) {
          e.printStackTrace();
        }
        if (buflen <= 0) {
          return false;
        }
      }
      return true;
    }

    private int readByte() {
      if (hasNextByte()) return buffer[ptr++];
      else return -1;
    }

    private static boolean isPrintableChar(int c) {
      return 33 <= c && c <= 126;
    }

    private void skipUnprintable() {
      while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
    }

    public boolean hasNext() {
      skipUnprintable();
      return hasNextByte();
    }

    public String next() {
      if (!hasNext()) throw new NoSuchElementException();
      StringBuilder sb = new StringBuilder();
      int b = readByte();
      while (isPrintableChar(b)) {
        sb.appendCodePoint(b);
        b = readByte();
      }
      return sb.toString();
    }

    public long nextLong() {
      if (!hasNext()) throw new NoSuchElementException();
      long n = 0;
      boolean minus = false;
      int b = readByte();
      if (b == '-') {
        minus = true;
        b = readByte();
      }
      if (b < '0' || '9' < b) {
        throw new NumberFormatException();
      }
      while (true) {
        if ('0' <= b && b <= '9') {
          n *= 10;
          n += b - '0';
        } else if (b == -1 || !isPrintableChar(b)) {
          return minus ? -n : n;
        } else {
          throw new NumberFormatException();
        }
        b = readByte();
      }
    }

    public int nextInt() {
      return (int) nextLong();
    }

    public int[] nextIntArray(int N, boolean oneBased) {
      if (oneBased) {
        int[] array = new int[N + 1];
        for (int i = 1; i <= N; i++) {
          array[i] = sc.nextInt();
        }
        return array;
      } else {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
          array[i] = sc.nextInt();
        }
        return array;
      }
    }

    public long[] nextLongArray(int N, boolean oneBased) {
      if (oneBased) {
        long[] array = new long[N + 1];
        for (int i = 1; i <= N; i++) {
          array[i] = sc.nextLong();
        }
        return array;
      } else {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
          array[i] = sc.nextLong();
        }
        return array;
      }
    }
  }

  static class Output extends PrintWriter {

    public Output(PrintStream ps) {
      super(ps);
    }

    public void print(int[] a, String separator) {
      for (int i = 0; i < a.length; i++) {
        if (i == 0) print(a[i]);
        else print(separator + a[i]);
      }
      println();
    }

    public void print(long[] a, String separator) {
      for (int i = 0; i < a.length; i++) {
        if (i == 0) print(a[i]);
        else print(separator + a[i]);
      }
      println();
    }

    public void print(String[] a, String separator) {
      for (int i = 0; i < a.length; i++) {
        if (i == 0) print(a[i]);
        else print(separator + a[i]);
      }
      println();
    }

    public void print(ArrayList a, String separator) {
      for (int i = 0; i < a.size(); i++) {
        if (i == 0) print(a.get(i));
        else print(separator + a.get(i));
      }
      println();
    }
  }

}


Measured memory_bytes: 28744