#include <iostream>

#include <map>

#include <string>

using namespace std;

#define REP(i,n) for(int i=0;i<(n);++i)

#define FOR(i,a,b) for(int i=(a);i<=(b);++i)

#define RFOR(i,a,b) for(int i=(a);i>=(b);--i)

class Solution {

int romanToInt(string s) {

map<char, int> mp;

mp['I'] = 1;

mp['V'] = 5;

mp['X'] = 10;

mp['L'] = 50;

mp['C'] = 100;

mp['D'] = 500;

mp['M'] = 1000;

int n = s.length();

int ret = mp[s[n - 1]];

RFOR(i,n-2,0) {

if (mp[s[i]] >= mp[s[i + 1]]) ret += mp[s[i]];

else ret -= mp[s[i]];

}

return ret;

}

};

int main() {

Solution s = Solution();

cout << s.romanToInt("MMCDLVI") << endl;

return 0;

}