#задача А
n = int(input())
A = [list(map(int, input().split())) for i in range (n)]
def func(A, n):
    for i in range(n):
        j = i
        while j <= n - 1:
            if ((A[i][j] != A[j][i]) or ((i == j) and (A[i][j] != 0))):
                return 1
            j+=1
    return 0
if (func(A, n)):
    print("NO")
else:
    print("YES")

#Задачи В
n = int(input())
A = [list(map(int, input().split())) for i in range (n)]
def func(A, n):
    s = 0
    for i in range(n):
        for j in range (n):
            if (A[i][j] == 1) :
                s += 1
            j+=1
    return int(s/2)
print(func(A, n))

#задача С
n = int(input())
A = [list(map(int, input().split())) for i in range (n)]
def func(A, n):
    s = 0
    for i in range(n):
        j = i
        while j <= n-1:
            if (A[i][j] == 1) :
                print (i+1 , j+1 , end = " ")
                print()
            j+=1

func(A, n)
#задача D
B = list(map(int, input().split()))
C = [[0] * B[0] for i in range (B[0])]
for o in range(B[1]):
    A = list(map(int, input().split()))
    for i in range (B[0]):
        if A[0] == i+1:
            for j in range (B[0]):
                if A[1] == j+1:
                        C[i][j] = 1
                        C[j][i] = 1
for i in range (B[0]):
    for j in range (B[0]):
        print(C[i][j], end = " ")
    print()

#задача Е
n = int(input())
A = [list(map(int, input().split())) for i in range (n)]
for i in range(n):
    s = 0
    for j in range(n):
        if A[i][j] == 1:
            s +=1
    print(s)