s = input().split()
base = int(s[0])*60+int(s[1])
plus = s[2][3]
diff = float(s[2][4:])*60

if plus=="+":
    diff -= 540
else:
    diff = (diff+540)*(-1)
base += diff

if base>=1440:
    base -= 1440
elif base<0:
    base += 1440
    
hour = "%02d"%int(base//60)
minit = "%02d"%int(base%60)
print(hour+":"+minit)