Help with my code.

[lastchance]

#include <iostream>
#include <string>
using namespace std;

int main()
{
   string input, subject, year;
   bool validSubject = true, validYear = true;
   
   cout << "Enter two characters: ";
   cin >> input;
   
        if (input[0] == 'M') subject = "Mathematics "           ;
   else if (input[0] == 'C') subject = "Computer Science "      ;
   else if (input[0] == 'I') subject = "Information technology ";
   else                      validSubject = false;

   int status = input[1] - '0';
   switch(status)
   {
      case 1: year = "Freshman" ;   break;
      case 2: year = "Sophomore";   break;
      case 3: year = "Junior"   ;   break;
      case 4: year = "Senior"   ;   break;
      default: validYear = false;
   }       
   
   if ( validSubject && validYear ) cout << subject + year << endl;
   if ( !validSubject ) cout << "Invalid major code"  << endl;
   if ( !validYear    ) cout << "Invalid status code" << endl;
}