6.1.8

#include <iostream>
#include <cmath>
using namespace std;

bool IsPalindrome (int n)
{
    int n1=n,NewN=0;
    int k=0;
    while (n1>0)
    {

        k=n1%10;
        NewN+=k;
        n1/=10;
        NewN*=10;
    }
    NewN/=10;
    return (NewN==n)? true:false;
}

int main()
{
    int n;
    cin>>n;
    int sum=0;
    for (int i=1;i<=n;i++)
        if (IsPalindrome(i)) sum++;
    cout<<sum;
    return 0;
}