S = str(input())
a = S[0]
b = S[1]
c = S[3]
d = S[4]

e = int(a)
f = int(b)
g = int(c)
h = int(d)

i = 10*e + f
j = 10*g + h

k = j + 5
if k > 59:
    k -= 60
    i += 1
if i > 23:
    i -= 24
    

l = str(i)
m = str(k)

if len(l) == 1:
    l = '0' + l
if len(m) == 1:
    m = '0' + m
    
print(l + ':' + m)