Module: (C++) For loop operator. Typical tasks

#include<iostream>      

using namespace std;   

main()  {      

  int i, s, b;      

  //The value of variable b must be entered from the keyboard. Write the appropriate operator here 

  s = 0;      

  for (i = __; i<=___; i++)  //instead of dashes, insert the initial and final values of the variable i 

     s = s + i;      

cout << s;    

}