"""
Thay the tu "ong" thanh "con ong ngoan"
"""


def insert2(s11, index, s22):
    for i2 in range(len(s22)-1, -1, -1):
        s11.insert(index, s22[i2])


s = "ong vang lon ton den nha ong nau choi"
length = len(s)

s2 = list(s)

for x in s2:
    print(x, end='')
print()

for i in range(length - 3, -1, -1):
    if s[i:i+3] == "ong":
        del s2[i:i+3]
        insert2(s2, i, "con ong ngoan")

for x in s2:
    print(x, end='')