import decimal
a,b,s = input().split()
a = int(a)
b = int(b)
s1 = decimal.Decimal(s[3:])-9
m = int(60*a+b+60*s1)
h = (m//60)%24
m = m % 60
h = str(h)
h = (2-len(h))*'0'+h
m = str(m)
m = (2-len(m))*'0'+m
print(h+':'+m)