/**
5. Write a function that accepts  one, two or three arguments of type double and outputs their sum. Use this function to write a program that asks the user to input {\em upto} three numbers, and prints out their sum. The program should include a loop that lets the user repeat this computation for new input values until the user wants to end the program.
**/
#include<iostream>
using namespace std;
void fun(double&);
void fun(double&,double&);
void fun(double&,double&,double&);

int main() {
  double a,b,c;
  int n;
  cout <<"How many numbers do you want to sum?"<<endl;
  cin >> n;

  if(n==1){
    fun(a);
  }
  else if(n==2){
    fun(a,b);
  }
  else if(n==3){
    fun(a,b,c);
  }
  else {
    cout<<"You need to answer 1,2, or 3"<<endl;
  }
}
void fun(double& a){
  cout<<"Enter the number"<<endl;
  cin>>a;
  cout<< "The sum is: "<<a<<endl;
}
void fun(double& a, double& b){
  cout<<"Enter the first number"<<endl;
  cin>>a;
  cout<<"Enter the second  number"<<endl;
  cin>>b;
  cout<<"The sum is: "<<a+b<<endl;
}
void fun(double& a, double& b, double& c){
  cout<<"Enter the first number"<<endl;
  cin>>a;
  cout<<"Enter the second  number"<<endl;
  cin>>b;
  cout<<"Enter the third number"<<endl;
  cin>>c;
  cout<<"The sum is: "<<a+b+c<<endl;
}