void perm(int &n)
{
    int putere=1,c,pc,nr=0;
    if(n>=10)
        do
    {
        c=n%10;
            nr=nr+c*putere;
            putere=putere*10;
        n=n/10;
    }while(n>=10);
    pc=n;
        n=nr*10+pc;
}