C++ :

#include <algorithm>
#include <cstdio>
using namespace std;
int n, ans;
int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) {
	int v = i % 10, t = i / 10, chk = 1;
	while (t) {
		if (t % 10 != v) chk = 0;
			t /= 10;
		}
		ans += chk;
	}
	printf("%d\n", ans);
	return 0;
}