T={M:1000,CM:900,D:500,CD:400,C:100,XC:90,L:50,XL:40,X:10,IX:9,V:5,IV:4,I:1}
gets
n=gets.split.map{|r|r.scan(/#{T.keys*?|}/).map{|c|T[c.intern]}.sum}.sum
n>3999?$><<:ERROR:(c,i=T.find{|c,i|i<=n};n-=i;$><<c)while n>0