What is wrong with my if else statement

#include <iostream> 
#include <iomanip> 
#include <conio.h> 
#include <string> 
#include <string.h>
using namespace std;

 int main()
{   
string K; 
cout<<"Sisestage isikukood:\n "; 
getline(cin, K);
              /* Küsin kasutajalt isikukoodi*/
std::string(str2) = K.substr (1,1);  
std::string(str3) = K.substr (2,2);  
std::string(str4) = K.substr (4,2); 
std::string(str5) = K.substr (6,2);  
std::string(str6) = K.substr (8,2);
 cout<<"Isikukoodi I andmed:\n ";
  if  (str2 == "1") 
  {                  
     cout<<" *mees\n"; 
  } 
  
  else if  (str2 == "2") 
  {                  
     cout<<" *naine\n"; 
  } 
    else if  (str2 == "3") 
  {                  
     cout<<" *mees\n";
  } 
      else if  (str2 == "4") 
  {                  
     cout<<" *naine\n"; 
  } 
          else if  (str2 == "5") 
  {                  
         cout<<" *mees\n"; 
  } 
          else if  (str2 == "6") 
  {   
      cout<<" *naine\n";           
  } 

    if  (str2 == "2" || str2== "1" ) 
  {                  
     cout<<"* sundis "<< str3 <<"." << str4<<"."<<"18"<< str5; 
  }
 else if  (str2 == "3" || str2== "4" ) 
  {                  
     cout<<"* sundis "<< str3 <<"." << str4<<"."<<"19"<< str5; 
  }
    else if  (str2== "5" || str2== "6" ) 
  {                  
     cout<<"* sundis "<< str3 <<"." << str4<<"."<<"20"<< str5; 
  }
   if  (str6 == "00") 
  {                  
     cout<<" * Kuressaare Haigla\n";         /* Leian haigla, kus on isikukoodi omanik sundinud */
  }  
   else if  (str6== "02") 
  {                  
     cout<<" * Ida-Tallinna Keskhaigla, Hiiumaa, Keila, Rapla haigla\n";
  }     
 else if  (str6 == "22") 
  {                  
     cout<<" *  Ida-Viru Keskhaigla\n";
  }  
  else if  (str6 == "27") 
  {                  
     cout<<" *  Maarjamõisa Kliinikum,Jõgeva Haigla \n";
  }  
   else if  (str6== "37") 
  {                  
     cout<<" *  Narva  Haigla \n";
  }     
     else if  (str6 == "42") 
  {                  
     cout<<" *  Pärnu Haigla \n";
  }    
      else if  (str6 == "47") 
  {                  
     cout<<" * Pelgulinna Sünnitusmaja , Haapsalu haigla \n";
  }              
  else if  (str6 == "49") 
  {                  
     cout<<" * Järvamaa haigla \n";
  }  
  else if  (str6 == "52") 
  {                  
     cout<<" * Rakvere, Tapa haigla \n"; 
  } 
     else if  (str6 == "57") 
  {                  
     cout<<" * Valga haigla \n"; 
  } 
    else if  (str6 == "60") 
  {                  
     cout<<" * Viljandi haigla \n"; 
  }
    else if  (str6 == "65") 
  {                  
     cout<<" *  Lõuna-Eesti Haigla (Võru), Põlva Haigla \n"; 
  }                       
  else  {                                                /*Tulemus,kui isikukood on sisestatud valesti*/ 
    cout<<" Sisestasite isikukoodi "<< K << " .Palun proovige uuesti.\n";  
}  
getch();
return 0; 
}