CifreImpare

int cifreImpare(int n)
{
    int s=0,cn=n,p=1;
    while(n)
    {
	    if(n%2==0)
	        s+=n%10*p,p*=10;
	    n/=10;
    }
    if(p==1||s==cn)
	    return -1;
    return s;
}