#include <bits/stdc++.h>

using namespace std;



string a[50];
int al[50] = {0};

int dva(vector<int> a){
    int carry = 0;
    int b = 2;
    int n = 0;
    while(carry == 0){
    for (int i=(int)a.size()-1; i>=0; --i) {
        long long cur = a[i] + carry * 1ll * 10;
        a[i] = int (cur / b);
        carry = int (cur % b);
    }
    if(carry == 0) n++;
    while (a.size() > 1 && a.back() == 0) a.pop_back();
    }
    return n;
}

int main(){
    int rrr;
    cin >> rrr;
    a[1] = "2";
    al[1] = 1;
    for(int i = 2; i <= 42; i++){
        if(al[i - 1] == i - 1){
            a[i] = "1" + a[i - 1];
            vector<int> x;
            for(int j = a[i].length() - 1; j > -1; j--) x.push_back(a[i][j] - 48);
            al[i] = dva(x);
        } else {
            a[i] = "2" + a[i - 1];
            vector<int> x;
            for(int j = a[i].length() - 1; j > -1; j--) x.push_back(a[i][j] - 48);
            al[i] = dva(x);
        }
    }
    cout << a[rrr];
    return 0;
}