def f(S):
    flag = 0
    if S[0] == "+":
        flag = 1
    S = S[1:]
    if "." not in S:
        return flag, int(S), 0
    x, y = S.split(".")
    x, y = int(x), int(y) * 6
    return flag, x, y

def g(x):
    x = str(x)
    if len(x) == 1:
        return "0" + x
    return x

a, b, s = input().split()
a, b = int(a), int(b)
a -= 9
flag, x, y = f(s[3:])
if flag:
    a += x
    b += y
    if b >= 60:
        b -= 60
        a += 1
    a %= 24
else:
    a -= x
    b -= y
    if b < 0:
        b += 60
        a -= 1
    a %= 24
print(g(a) + ":" + g(b))