#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<ctime>
#include<queue>
#include<set>
#include<map>
#include<stack>
#include<bitset>

#define pb push_back
#define mp make_pair

using namespace std;

template<typename T>inline void upmin(T &x,T y) { y<x?x=y:0; }
template<typename T>inline void upmax(T &x,T y) { x<y?x=y:0; }

typedef unsigned int u32;
typedef long long LL;
typedef unsigned long long ULL;
typedef long double lod;
typedef pair<int,int> PR;
typedef vector<int> VI;

const lod pi=acos(-1);
const int oo=1<<30;
const LL OO=1e18;
const int mod=1e9+7;

int gi() {
	int w=0;bool q=1;char c=getchar();
	while ((c<'0'||c>'9') && c!='-') c=getchar();
	if (c=='-') q=0,c=getchar();
	while (c>='0'&&c <= '9') w=w*10+c-'0',c=getchar();
	return q? w:-w;
}

inline int qpow(int x,int y) {
	int ans=1;
	while (y) {
		if (y&1) ans=1LL*ans*x%mod;
		x=1LL*x*x%mod;y>>=1;
	}
	return ans;
}

inline int F(int len,int s) {
	if (len<=7) return 0;
	return (9LL*qpow(10,len-1)-s)%mod;
}

int main()
{
	int S=gi(),l,r,s=0,pl=1,pr=1,L=0,R=0,ans=0,i;
	for (l=1,r=1;l<1e7;l++) {
		for (;s<S;r++) {
			if (r==pr) pr*=10,R++;
			s+=R;
		}
		ans+=s==S;
		if (l==pl) pl*=10,L++;
		s-=L;
	}
	for (i=1;i*i<=S;i++)
		if (!(S%i)) {
			(ans+=F(i,S/i))%=mod;
			if (i*i!=S)
				(ans+=F(S/i,i))%=mod;
		}
	cout<<(ans+S/8+mod)%mod;
	return 0;
}

### Prompt

Construct a cpp code solution to the problem outlined:

For a positive integer n, let us define f(n) as the number of digits in base 10.

You are given an integer S. Count the number of the pairs of positive integers (l, r) (l \leq r) such that f(l) + f(l + 1) + ... + f(r) = S, and find the count modulo 10^9 + 7.

Constraints

* 1 \leq S \leq 10^8

Input

Input is given from Standard Input in the following format:


S


Output

Print the answer.

Examples

Input

1


Output

9


Input

2


Output

98


Input

123


Output

460191684


Input

36018


Output

966522825


Input

1000


Output

184984484

### Response

```cpp
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<ctime>
#include<queue>
#include<set>
#include<map>
#include<stack>
#include<bitset>

#define pb push_back
#define mp make_pair

using namespace std;

template<typename T>inline void upmin(T &x,T y) { y<x?x=y:0; }
template<typename T>inline void upmax(T &x,T y) { x<y?x=y:0; }

typedef unsigned int u32;
typedef long long LL;
typedef unsigned long long ULL;
typedef long double lod;
typedef pair<int,int> PR;
typedef vector<int> VI;

const lod pi=acos(-1);
const int oo=1<<30;
const LL OO=1e18;
const int mod=1e9+7;

int gi() {
	int w=0;bool q=1;char c=getchar();
	while ((c<'0'||c>'9') && c!='-') c=getchar();
	if (c=='-') q=0,c=getchar();
	while (c>='0'&&c <= '9') w=w*10+c-'0',c=getchar();
	return q? w:-w;
}

inline int qpow(int x,int y) {
	int ans=1;
	while (y) {
		if (y&1) ans=1LL*ans*x%mod;
		x=1LL*x*x%mod;y>>=1;
	}
	return ans;
}

inline int F(int len,int s) {
	if (len<=7) return 0;
	return (9LL*qpow(10,len-1)-s)%mod;
}

int main()
{
	int S=gi(),l,r,s=0,pl=1,pr=1,L=0,R=0,ans=0,i;
	for (l=1,r=1;l<1e7;l++) {
		for (;s<S;r++) {
			if (r==pr) pr*=10,R++;
			s+=R;
		}
		ans+=s==S;
		if (l==pl) pl*=10,L++;
		s-=L;
	}
	for (i=1;i*i<=S;i++)
		if (!(S%i)) {
			(ans+=F(i,S/i))%=mod;
			if (i*i!=S)
				(ans+=F(S/i,i))%=mod;
		}
	cout<<(ans+S/8+mod)%mod;
	return 0;
}

```