int main()
{
    int a = 1;
    int b = 2;
    printf("a=%d,b=%d\n",a,b);
    a=a^b;
    b=a^b;
    a=a^b;
    printf("a=%d,b=%d\n",a,b);
    return 0;
}

int main()
{
    int a = 1;
    int b = 2;
    printf("a=%d,b=%d\n",a,b);
    a=a^b;
    b=a^b;
    a=a^b;
    printf("a=%d,b=%d\n",a,b);
    return 0;
}