a,b,S = map(str, input().split())

a = int(a)
b = int(b)
c = 0
d = 0
for i in range(4, len(S)):
    if S[i] == ".":
        continue
    if 4 <= i <= 5:
        c = c*10 + int(S[i])
    else:
        d = 6*int(S[i])

if S[3] == "+":
    delta = c*60+d - 540
else:
    delta = -c*60-d -540

time = a*60+b + delta
h = (time//60)%24
m = time%60
if h < 10:
    h = "0" + str(h)
else:
    h = str(h)
if m < 10:
    m = "0" + str(m)
else:
    m = str(m)
print(h+":"+m)