Program to swap two variables without using third or temp variable

Program Logic Steps:
Store sum of both in var1.
Subtract var2 from var1 and store it in var2 (now var2 has value of var1) .
Subtract var2 from var1 and store it in var1 (now var1 has value of var2).

C++ Program

#include<iostream>
using namespace std;
int main() {
	int var1, var2;
	cout<<"Enter value for first integer:  ";
	cin>>var1;
	cout<<"Enter value for second integer:  ";
	cin>>var2;
	cout<<" Values Before swapping:  "<<endl;
	cout<<"First Integer ="<<var1<<endl;
	cout<<"Second Interger ="<<var2<<endl;
	var1=var1+var2;
	var2=var1-var2;
	var1=var1-var2;
	cout<<" Values After swapping:  "<<endl;
	cout<<"First Integer ="<<var1<<endl;
	cout<<"Second Interger ="<<var2<<endl;
	return 0;
}