#include<bits/stdc++.h>
using namespace std;
short x[10],y[105],z[105],u[105];
int main()
{
	int j,i,h,n,l=100,c=0;
	bool f=false;
	cin>>n;
	y[1]=1;
	while (c!=n)
	{
    	c++;
		x[0]=c%10;
		x[1]=c/10;
		for (j=0;j<=1;j++)  //first
    	{
        	for (i=1;i<=l;i++)
        	{
        	    u[i+j]+=x[j]*y[i];
        	    u[i+j+1]+=(u[i+j]/10);
        		u[i+j]%=10;
        	}
    	}
		for (i=1;i<=l;i++)
    	{
    	    y[i]=u[i];
    	}
    	memset(u,0,sizeof(u));
    	
    	f=false;
		for (i=l;i>=1;i--)
		{
   			if (f==false&&y[i]==0) continue;
    		else f=true;
		    z[i]+=y[i];
        	z[i+1]+=(z[i]/10);
        	z[i]%=10;
		}
	}
	f=false;
    for (i=l;i>=1;i--)
    {
        if (f==false&&z[i]==0) continue;
        else f=true;
        cout<<z[i];
    }
    if (f==false) cout<<"0";
	return 0;
}