#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <numeric>
#include <sstream>
#include <iostream>
#include <iomanip>
#define _USE_MATH_DEFINES
#include <cmath>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cfloat>
#include <cmath>
#include <ctime>
#include <cassert>
#include <cctype>
#include <cstdio>
#include <cassert>
using namespace std;

#define EPS 1e-12
#define ull unsigned long long
#define ll long long
#define VI vector<ll>
#define PII pair<ll, ll> 
#define VVI vector<vector<ll> >
#define VVVI vector<vector<vector<ll>>>
#define VVVVI vector<vector<vector<vector<ll>>>>
#define REP(i,n) for(ll i=0,_n=(n);(i)<(ll)_n;++i)
#define REPR(i,n) for(ll i=(ll)(n)-1;0<=(i);--i)
#define RANGE(i,a,b) for(ll i=(ll)a,_b=(ll)(b);(i)<_b;++i)
#define RANGER(i,a,b) for(ll i=(ll)(b)-1,_a=(ll)(a);(_a)<=i;--i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
#define ALLR(c) (c).rbegin(), (c).rend()
#define PB push_back
#define MP(a, b) make_pair(a, b)
#define POPCOUNT __builtin_popcount
#define POPCOUNTLL __builtin_popcountll
#define CLEAR(table, v) memset(table, v, sizeof(table));
#define UNIFORM_DOUBLE(a, b) (((b-a)*(double)rand()/RAND_MAX)+a) // [a, b) 
#define UNIFORM_LL(a, b) (ll)UNIFORM_DOUBLE(a, b) // [a, b) 
#define IN(v, lo, hi) ((lo)<=(v) && (v)<(hi))
#define DD(v) cout<<#v<<": "<<v<<endl
#define FI first
#define SE second
template <typename T0, typename T1> std::ostream& operator<<(std::ostream& os, const map<T0, T1>& v) { for( typename map<T0, T1>::const_iterator p = v.begin(); p!=v.end(); p++ ){os << p->first << ": " << p->second << " ";} return os; }
template <typename T0, typename T1> std::ostream& operator<<(std::ostream& os, const pair<T0, T1>& v) { os << v.first << ": " << v.second << " "; return os; }
template <typename T> std::ostream& operator<<(std::ostream& os, const vector<T>& v) { for( int i = 0; i < (int)v.size(); i++ ) { os << v[i] << " "; } return os; }
template <typename T> std::ostream& operator<<(std::ostream& os, const set<T>& v) { vector<T> tmp(v.begin(), v.end()); os << tmp; return os; }
template <typename T> std::ostream& operator<<(std::ostream& os, const deque<T>& v) { vector<T> tmp(v.begin(), v.end()); os << tmp; return os; }
template <typename T> std::ostream& operator<<(std::ostream& os, const vector<vector<T> >& v) { for( int i = 0; i < (int)v.size(); i++ ) { os << v[i] << endl; } return os; }
template<typename T>void maxUpdate(T& a, T b) {a = max(a, b);}
template<typename T>void minUpdate(T& a, T b) {a = min(a, b);}

#define MOD 1000000007LL
#define INF (1LL<<60)

ll f(ll d, ll h, ll t, ll mid) {
	ll v = h;
	REP(i, d-1) v*=10;
	v+=t;
	v+=mid*10;
	return v;
}
ll pow10(ll p) {
	ll v=1;
	REP(i, p) v*=10;
	return v;
}
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	ll N;
	while(cin>>N) {
		ll ans = 0;
		RANGE(i, 1, N+1) {
			// head of i
			int h = 0;
			int v = i;
			while(v) {
				h = v%10;
				v/=10;
			}
			int t = i%10;
			if(t==0) continue;
//			DD(h);DD(t);
			ll lans = 0;
			// 1
			if(h==t) lans++;
			// 2
			ll v2 = t*10+h;
			if(v2<=N) lans++;
			// 3-6
			RANGE(d, 3, 7) {
				ll mx = pow10(d-2);
				ll ub = f(d, t, h, mx-1);
				if(ub<=N) {
					lans+=mx;
//					DD(d);DD(mx);
					continue;
				}
				ll lb = f(d, t, h, 0);
				if(!(lb<=N)) continue;
				// lo is ok, hi is NG
				ll lo=0, hi=mx;
				while(lo+1<hi) {
					ll mid = (lo+hi)/2;
					ll v = f(d, t, h, mid);
					if(v<=N) lo=mid; else hi=mid;
				}
				lans+=hi;
//				DD(d);DD(hi);
			}
//			DD(i);
//			DD(lans);
			ans += lans;
		}
		
		cout<<ans<<endl;
//		break;
	}
	
	return 0;
}


Measured memory_bytes: 256