inp  = input()     # Typed line
outp = input()     # Output line

# Find first different character in inp and outp
for i in range( len(inp) ):
   if ( inp[i] != outp[i] ):
       print(f"First diff char: {inp[i]} != {outp[i]}")

       firstDiffCharInOutp = outp[i]
       print(f"firstDiffCharInOutp = {firstDiffCharInOutp}")

       break

# Find next different char in input
for j in range(i+1, len(inp)):
   if (inp[j] != inp[i]):
      break;  

print(f"Next diff char in input = {inp[j]}")

# Find first special character (quiet or silly)
if ( firstDiffCharInOutp == inp[j] ):
   # We found "quiet"
   quiet = inp[i]
   print(f"** quiet = {quiet}")
   silly = None
   sillyOut = None
else:
   # We found "silly"
   silly = inp[i]
   print(f"** silly = {silly}")
   sillyOut = firstDiffCharInOutp
   quiet = None


# Now find the 2nd special character

inpSet  = set(inp)
outpSet = set(outp)

if ( silly == None ):
   # Find silly
   print(f"Find silly....")

   inpSet.remove(quiet)		# Remove quiet from inpSet

   # Find silly
   diff1 = inpSet.difference(outpSet)
   silly = list(diff1)[0]

   # Find sillyOut
   diff2 = outpSet.difference(inpSet)
   sillyOut = list(diff2)[0]

else:
   # Find quiet

   if ( len(inp) == len(outp) ):
       quiet = '-'
   else:
       diff1 = inpSet.difference(outpSet)
       quiet = list(diff1)[0]

print(silly, sillyOut)
print(quiet)