Coloring cube

def f(n):
    a = [[[None for i in range(n)] for j in range(n)] for k in range(n)]
    for i in range(n):
        for j in range(n):
            for k in range(n):
                a[i][j][k] = (("R" if (i+j+k)%3 == 1 else "G") if (i+j+k)%3 != 2 else "B")
    return a

n = int(input())
res = f(n)
for i in range(n):
    if i > 0:
        print()
    for j in range(n):
        print(" ".join(res[i][j]))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED