import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  try {
    for (; ; ) {
      const N = readInt;
      auto A = new long[][](N, N);
      int I = -1, J = -1;
      foreach (i; 0 .. N) foreach (j; 0 .. N) {
        const a = readToken;
        if (a == "?") {
          I = i;
          J = j;
        } else {
          A[i][j] = a.to!long;
        }
      }
      
      long ans;
      if (N == 1) {
        ans = 1;
      } else {
        foreach (j; 0 .. N) if (j != J && A[I][j] != 0) {
          long sum;
          foreach (i; 0 .. N) if (i != I) {
            sum -= A[i][j] * A[i][J];
          }
          debug {
            writefln("j = %s; %s / %s", j, sum, A[I][j]);
          }
          assert(sum % A[I][j] == 0);
          ans = sum / A[I][j];
          goto found;
        }
        assert(false);
       found:
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}