// 謎AC
// 残ってるのの1/10を足していって最後に残ってるのの1/3を
// 足して最後に-1するとなぜか答えが合います

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include "bits/stdc++.h"
#define REP(i,a,b) for(int i=a;i<b;++i)
#define rep(i,n) REP(i,0,n)
#define ll long long
#define ull unsigned ll
typedef long double ld;
#define ALL(a) begin(a),end(a)
#define ifnot(a) if(not a)
#define dump(x)  cerr << #x << " = " << (x) << endl
using namespace std;

// #define int ll
#ifdef _MSC_VER
const bool test = true;
#else 
const bool test = false;
#endif

int dx[] = { 0,1,0,-1 };
int dy[] = { 1,0,-1,0 };
#define INF (1 << 28)
ull mod = (int)1e9 + 7;
//.....................
#define MAX (int)1e6 + 5

int P;

void mode1() {
	ull cnt = 0;
	ull last = 1;
	rep(i, P) last *= 10;
	ull rest = last;
	rep(i, P) {
		cnt += rest / 10;
		rest -= rest / 10;
	}
	cnt += rest / 3;
	cnt--;
	cout << cnt << endl;
}

signed main() {
	int mode = 0;

	while (cin >> P) {
		mode1();
	}
	return 0;
}