from math import ceil
a, b, S = input().rstrip().split()
a = int(a)
b = int(b)
c = float(S[3:]) - 9
c *= 60
d = b + (-1 if c < 0 else 1) * ceil(abs(c))
b = d % 60
a += d // 60
if a > 23:
    a -= 24
elif a < 0:
    a = 24 + a
print(f"{a:02}:{b:02}")