//SOL
public static int Solve(int num)
{
string sNum = Math.Abs(num) + "";
int sign = num < 0 ? -1 : 1;
num = Helfer.GetNumber(sNum[sNum.Length - 1]);
for (int i = sNum.Length - 2; i >= 0; i--)
{
int tmp = num * 10 + Helfer.GetNumber(sNum[i]);
if (tmp <= num)
{
return(0);
}
num = tmp;
}
return(num);
}