#include <iostream>
#include <string>
#include <string.h>
using namespace std;
string add(string s1,string s2)
{
	const int MAX_NUM=200;
	int op1[MAX_NUM];
	int op2[MAX_NUM];
	int i;
	for (i=0;i<MAX_NUM;i++){
		op1[i]=0;
		op2[i]=0;
	}
	size_t sLen1=s1.size();
	size_t sLen2=s2.size();
	i=(int)(sLen1-1);
	int j=0;
	while (i>=0){
		op1[j++]=s1[i]-'0';
		i--;
	}
	j=0;
	i=(int)(sLen2-1);
	while (i>=0){
		op2[j++]=s2[i]-'0';
		i--;
	}
	size_t sLen=max(sLen1,sLen2);
	int C=0;
	for (i=0;i<sLen;i++){
		op1[i]+=op2[i];
	}
	for (i=0;i<sLen;i++){
		op1[i] +=C;
		if (op1[i]>=10){
			op1[i]-=10;
			C=1;
		}else{
			C=0;
		}
	}
	if (C>0){
		op1[i]=C;
		C=0;
		sLen++;
	}
	string s;
	for (i=sLen-1;i>=0;i--){
		s+=op1[i]+'0';
	}
	return s;
}
int alignDecimal(string &S1,string &S2)
{
	string s;
	string s1=S1;
	string s2=S2;

	size_t s1Len=s1.size();
	size_t s2Len=s2.size();
	size_t s1DecLen=0;
	size_t s2DecLen=0;
	char *p=strchr((char*)s1.c_str(),'.');
	if (p){
		s1DecLen = s1Len - (p-s1.c_str())-1;
	}
	p=strchr((char*)s2.c_str(),'.');
	if (p){
		s2DecLen = s2Len - (p-s2.c_str())-1;
	}
	size_t MaxDecLen=max(s1DecLen,s2DecLen);
	int i;
	for (i=0;i<s1Len;i++){
		if (s1[i]!='.'){
			s+=s1[i];
		}
	}
	for (i=0;i<MaxDecLen-s1DecLen;i++){
		s+='0';
	}
	s1=s;
	s.clear();
	for (i=0;i<s2Len;i++){
		if (s2[i]!='.'){
			s+=s2[i];
		}
	}
	for (i=0;i<MaxDecLen-s2DecLen;i++){
		s+='0';
	}
	s2=s;
	S1=s1;
	S2=s2;
	return MaxDecLen;
}
//大小数和演算12345678901234567890.123456789+12345678901234567890.98654321
string addDecimal(string s1,string s2)
{
	int MaxDecLen = alignDecimal(s1,s2);
	string s=add(s1,s2);
	int s1Len=s.length();
	if (MaxDecLen>0){
		s.insert(s1Len-MaxDecLen,".");
	}
	return s;
}

int main(int argc, char* argv[])
{
	string D="0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991";
	int N;
	cin>>N;
	int i;
	string s=D;
	for (i=1;i<N;i++){
		s=addDecimal(s,D);
	}
	cout<<s<<endl;

	return 0;
}