static public long invModN(long a, long b)
{
bezout c = idBezout(a, b);
if (c.mcd != 1)
{
throw new ArithmeticException("No existe módulo para " + a + " mod " + b);
}
if (c.alfa < 0)
{
return(c.alfa + b);
}
return(c.alfa);
}
static public string toStringBezout(long a, long b)
{
bezout c = idBezout(a, b);
return(c.mcd + "=" + a + "*(" + c.alfa + ")+" + b + "*(" + c.beta + ")");
}