#include<bits/stdc++.h>
using namespace std;
string times(string s1,string s2){
	string res;
	int len1=s1.size(),len2=s2.size(),len=len1+len2,num1[2000],num2[2000],ji[2000];
	for(int i=0;i<len1;i++)num1[len1-i]=int(s1[i]-'0');
	for(int i=0;i<len2;i++)num2[len2-i]=int(s2[i]-'0');
	for(int i=1;i<=len1;i++)for(int j=1;j<=len2;j++){
		ji[i+j-1]+=num1[i]*num2[j];
		ji[i+j]+=ji[i+j-1]/10;
		ji[i+j-1]%=10;
	}
	for(int i=len;i>0;i--)res+=char(ji[i]+'0');
	return res;
}
string add(string s1,string s2){
	string res;
	int len1=s1.size(),len2=s2.size(),len=max(len1,len2),num1[2000],num2[2000],sum[2000];
	for(int i=0;i<len1;i++)num1[len1-i-1]=int(s1[i]-'0');
	for(int i=0;i<len2;i++)num2[len2-i-1]=int(s2[i]-'0');
	for(int i=0;i<len;i++){
		if(num1[i]+num2[i]>10){
			num1[i+1]++;
			num1[i]-=10;
		}
		sum[i]=num1[i]+num2[i];
	}
	for(int i=len-1;i>=0;i--)res+=char(sum[i]+'0');
	return res;
}
int n;
string res1,res2="0";
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		res1="1";
		for(int j=1;j<=i;j++)res1=times(res1,to_string(j));
		res2=add(res2,res1);
	}
	cout<<res2;
	return 0;
}