a, b, s = input().split()

a = int(a)
b = int(b)
t = a * 60 + b
if '.' not in s:
    x = int(s[3:])
    x *= 60
else:
    x = s[3:]
    x, f = x.split('.')
    x = int(x)
    x *= 60
    f = int(f)
    f *= 6
    if x >= 0:
        x += f
    else:
        x -= f
d = x - 60 * 9
t += d
if t < 0:
    t += 24 * 60
elif t >= 24 * 60:
    t -= 24 * 60
h, m = divmod(t, 60)
print(f"{h:02}:{m:02}")