while True:
a,b=input().split()
S_L=list(map(int,a.split(":")))
D_L=list(map(int,b.split(":")))
if sum(S_L+D_L) == 0:
break
S = S_L[0]*60 +S_L[1]
D = D_L[0]*60 +D_L[1]
T= S+D
check = 0
check = T // 1440
print("%02d:%02d" %((T//60)%24,T%60),end="")
if check > 0:
print(" +{}".format(check),end="")
print()