#include<iostream>

using namespace std;
#define repeat(i, n) for(int i=0;i<(n);i++)
#define reveat(i, n) for(int i=(n-1);i>=0;i--)

int main(){
   string D="1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991";
   int N;
   cin>> N;

   string _D=D;
   repeat(n, N-1){
      bool car=false;
      int diff=_D.size()-D.size();
      reveat(i, D.size()){
         int d=(_D[i+diff]-'0')+(D[i]-'0')+car;
         car=(d>=10);
         d%=10;
         _D[i+diff]=d+'0';
      }
      reveat(i, diff){
         int d=(_D[i]-'0')+car;
         car=(d>=10);
         d%=10;
         _D[i]=d+'0';
      }
      if(car) _D="1"+_D;
   }

   repeat(i, _D.size()){
      if(_D.substr(i).size()==190){
         if(i==0) cout<< "0";
         cout<< ".";
      }
      cout<< _D[i];
   }cout<< endl;

   return 0;
}