class Solution:
    def romanToInt(self, s: str) -> int:
        a = {'I':1, 'V':5, 'X':10, 'L':50, 'C':100, 'D':500, 'M':1000}  
        count=0
        l=list(s)
        
        for i in range(len(l)):  
        
                 if i<len(l)-1 and a[l[i]]<a[l[i+1]]:
                    count-=a[l[i]]
                 else:
                    count+=a[l[i]]
         
        return count