# coding: utf-8
# Here your code !
x = input().split(":")

a = int(x[0])
b = int(x[1])

if a < 9:
    if b < 5:
        print("0" + str(a) + ":0" + str(b + 5))
    elif b <= 54:
        print("0" + str(a) + ":" + str(b + 5))
    elif b >= 55:
        print("0" + str(a + 1) + ":0" + str(b - 55))
        
elif a == 9:
    if b < 5:
        print("0" + str(a) + ":0" + str(b + 5))
    elif b <= 54:
        print("0" + str(a) + ":" + str(b + 5))
    elif b >= 55:
        print(str(a + 1) + ":0" + str(b - 55))

elif a <= 23 and b <= 54:
    if b < 5:
        print(str(a) + ":0" + str(b + 5))
    elif b <= 54:
        print(str(a) + ":" + str(b + 5))
    elif b >= 55:
        print(str(a + 1) + ":0" + str(b - 55))

else:
    print("00:0" + str(b - 55))