#include <iostream>
#include <cstdlib>
using namespace std;
int getIndex(char rom[7],char c)
{
	for(int i = 0;i<7;i++)
	{
		if(rom[i] == c)
		{
			return i;
		}
	}
	return -1;
}
int main()
{
    char rom[7] = {'I','V','X','L','C','D','M'};
    int dec[7] = {1,5,10,50,100,500,1000};
    char str[255] = {' '};
    int res = 0;
    char c1 = ' ',c2 = ' ';
    int index = 0;
	int a = 0, b = 0;
    while(1)
    {
    	c1 = getchar();
    	if(c1 == '\n') break;
    	c2 = getchar();
    	a = dec[getIndex(rom,c1)];
    	b = dec[getIndex(rom,c2)];
    	if(c2 == '\n') {res += a; break;};
    	if(a < b) res += b - a;
		else if(a >= b) res += a + b;
	}
	cout << res;
    return 0;
}