i = int(input())
g = [int(i) for i in input().split()]
t = 0
y = 0
u = 0

for e in range(i):
    if g[e] == 1:
        t += 1
    elif g[e] == 2:
        y += 1
    else:
        u += 1

for q in range(t):
    print("1",end=" ")
for q in range(y):
    print("2",end=" ")
for q in range(u):
    print("3",end=" ")
print()

Here where I fine it : https://steam.oxxostudio.tw/category/python/zerojudge/d587.html