暗号解読

暗号について、どう解読したかを載せておきます。

届いたメール
1通目
Your half of the encrypted passcode is [CXVIII CXIX CIX LII LVI CV CII C] and your hint is [Roman/Decimal].
The format for the full encrypted passcode is xxx##keyword####xxx where # equals numbers and x equals letters
2通目
Your half of the encrypted passcode is [XV XLIX LV LIV LII CXX CXIII CXX] and your hint is [Roman/Decimal].