g=0
h=0
Roman=["I","V","X","L","C","D","M"]
Roman_number=["1","5","10","50","100","500","1000"]
Roman_total=[]
Roman_total_2=[]
a=[]
b=[]
I="1"
V="5"
X="10"
L="50"
C="100"
D="500"
M="1,000"
#print('''I="1"
#V="5"
#X="10"
#L="50"
#C="100"
#D="500"
#M="1,000"''')
#print("""please insert two word
#ex.M L""")
while True:
x=input()
if x=="#":
break
else:
ipt=x.split()
a=ipt[0]
b=ipt[1]
for i in range((len(a))*(7)):
# print("len(a)=",len(a))
if a=="#":
False
if a[h] == (Roman[g]):
# print(Roman_number[g])
Roman_total.append(int(Roman_number[g]))
g+=1
if h<(len(a)-1):
# print("h=",h)
h+=1
g=0
elif (len(a)-1)==h:
break
else:
g+=1
g=0
h=0
for i in range((len(b))*(7)):
# print("len(b)",len(b))
if b[h] == (Roman[g]):
# print(Roman_number[g])
Roman_total_2.append(int(Roman_number[g]))
g+=1
if h<(len(b)-1):
# print("h=",h)
h+=1
g=0
elif h==(len(b)-1):
break
else:
g+=1
h=0
g=0
sum_Roman=abs((sum(Roman_total)-sum(Roman_total_2)))
# print(sum_Roman)
if sum_Roman==0:
print("ZERO")
# else :
# print(sum_Roman)
Roman_total=[]
Roman_total_2=[]
Thousand=sum_Roman//1000
hundred=(sum_Roman%1000)//100
one=sum_Roman%10
ten=(sum_Roman%1000)%100//10
# print(Thousand,hundred,ten,one)
if Thousand!=0:
for i in range(Thousand):
print("M"*Thousand,end="")
if hundred<5:
print("C"*hundred,end="")
if hundred==5:
print("D",end="")
if hundred>5 and hundred!=9:
print("D","C"*(hundred-5),sep="",end="")
if hundred==9:
print("CM",end="")
if ten<5:
print("X"*ten,end="")
if ten==5:
print("L",end="")
if ten>5 and ten!=9:
print("L","X"*(ten-5),sep="",end="")
if ten==9:
print("XC",end="")
if one<5:
print("I"*one,end="")
if one==5:
print("V",end="")
if one>5 and one!=9:
print("V","I"*(one-5),sep="",end="")
if one==9:
print("IX",end="")
這些程式就是過不了