n = int(input())
matrix = []
r = -1
c = -1

for i in range(n):
    row = input().split()
    for j in range(n):
        if row[j] == '?':
            r = i
            c = j
    matrix.append(row)

if n == 1:
    print(1)
else:
    x_candidates = []
    for k in range(n):
        if k == c:
            continue
        a_rk = int(matrix[r][k])
        if a_rk == 0:
            continue
        sum_part = 0
        for i in range(n):
            if i == r:
                continue
            a_ic = int(matrix[i][c])
            a_ik = int(matrix[i][k])
            sum_part += a_ic * a_ik
        numerator = -sum_part
        if numerator % a_rk != 0:
            pass
        x_candidate = numerator // a_rk
        x_candidates.append(x_candidate)
    print(x_candidates[0])