Answer:
// Program is written in C++ programming language
/ Comments are used for explanatory purpose
// Program starts here
#include<bits/stdc++.h> 
using namespace std; 
 //Declare a function named value to represent the symbols of Roman Numerals 
int value(char xy) 
{ 
 if (xy == 'I') { return 1; }
 if (xy == 'V') { return 5; }
 if (xy == 'X') { return 10; }
 if (xy == 'L') { return 50; }
 if (xy == 'C') { return 100; }
 if (xy == 'D') { return 500; }
 if (xy == 'M') { return 1000; }
 return -1; 
} 
// Convert to numbers , taking Variable named input as input
int Converted(string &input) 
{ 
// Declare a variable to store the calculated output
int calc;
 // Set to 0
 calc = 0; 
 // Iterate through input from 0 to the last character
 for (int i=0; i<input.length(); i++) 
 { 
 int check1 = value(input[i]); 
 if (i+1 < input.length()) 
 { 
 int check12= value(input[i+1]); 
 // Comparing both values 
 if (check1>= check2) 
 { 
 calc+ =check1;
 } 
 else
 { 
 calc+ =check2 - check1;
 i++;
 } 
 } 
 else
 { 
 calc+ =check1;
 } 
 } 
 return calc; 
} 
 
// Main method starts here
int main() 
{ 
 // String input declaration
string inp;
cout<"Enter any valid Roman numeral";
 cout << "Result is "
 << Converted(inp);
 return 0; 
}