另外一道双倍经验都过了，这道就是过不了

#include <iostream>
#include <cstdio>

using namespace std;

struct flac
{
	long long son,mom;
};

long long gcd(long long a,long long b) {while(b^=a^=b^=a%=b);return a;}

flac build(long long son,long long mom)
{
	flac now;
	now.mom=mom;
	now.son=son;
	return now;
}

flac sum(flac a,flac b)
{
	flac now;
	now.son=a.mom*b.son+b.mom*a.son;
	now.mom=a.mom*b.mom;
	long long g=gcd(now.son,now.mom);
	now.son/=g;
	now.mom/=g;
	return now;
}

flac mul(flac a,long long n)
{
	flac now;
	now.son=a.son*n;
	now.mom=a.mom;
	long long g=gcd(now.son,now.mom);
	now.son/=g;
	now.mom/=g;
	return now;
}

long long findsize(long long a)
{
	long long ans=1;
	for(long long i=1;i<=a;i*=10,ans++);
	return ans;
}

void print(flac a)
{
	if(a.mom==1)
	{
		cout<<a.son<<endl;
		return ;
	}
	int dai=a.son/a.mom;
	if(dai==0)
	{
		cout<<a.son%a.mom<<endl;
		for(int i=1;i<=findsize(a.mom)-1;i++) cout<<'-';
		cout<<endl<<a.mom<<endl;
	}
	else
	{
		for(int i=1;i<=findsize(dai)-1;i++) cout<<' ';
		cout<<a.son%a.mom<<endl;
		cout<<dai;
		for(int i=1;i<=findsize(a.mom)-1;i++) cout<<'-';
		cout<<endl;
		for(int i=1;i<=findsize(dai)-1;i++) cout<<' ';
		cout<<a.mom<<endl;
	}
}

int main()
{
	long long n;
	while(cin>>n)
	{
		flac ans=build(0,1);
		for(long long i=1;i<=n;i++)
		{
			ans=sum(ans,build(1,i));
		}
		ans=mul(ans,n);
		print(ans);
	}
}