swapping two value without third variable

/* swapping of two numbers without used of third variable*/
#include<stdio.h>
#include<conio.h>
int main()
{
    int no1,no2;//variable declaration
    printf("\nEnter No 1=");
    scanf("%d",&no1);
    printf("\nEnter No 2=");
    scanf("%d",&no2);
    printf("\n Before Swapping value of no1 and no2 is %d and %d",no1,no2);
    no1=no1+no2;
    no2=no1-no2;
    no1=no1-no2;
    printf("\n After Swapping value of no1 and no2 is %d and %d",no1,no2);
    return 0;
}