a,b,s = input().split()
d = float(s[3:]) - 9
da, db = map(int, ("{:.1f}".format(d)).split("."))
if d < 0:
    db *= -1
b = int(b) + db * 6
a = int(a) + da + (b >= 60) - (b < 0)
print("{:02d}:{:02d}".format(a%24, b%60))