#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

#include<cmath>

using namespace std;

#define maxn 105

#define mod 100000000

int n;

struct bignum{

	int len;

	int a[maxn*10];

	bool operator <(const bignum &b)const{

		if (len!=b.len) return len<b.len;

		for (int i=len;i;i--) if (a[i]<b.a[i]) return 1;

		return 0;

	}

	bignum operator +(const bignum &b){

		bignum c;c.len=max(len,b.len);memset(c.a,0,sizeof(c.a));

		for (int i=1;i<=c.len;i++){

			c.a[i]+=a[i]+b.a[i];

			if (c.a[i]>mod) c.a[i+1]=c.a[i]/mod,c.a[i]%=mod;

		}

		if (c.a[c.len+1]) c.len++;

		return c;

	}

	bignum operator -(const bignum &b){

		bignum c;c.len=max(len,b.len);memset(c.a,0,sizeof(c.a));

		for (int i=1;i<=c.len;i++){

			c.a[i]=a[i]-b.a[i];

			if (c.a[i]<0) c.a[i]+=mod,a[i+1]--;

		}

		for (;!c.a[c.len]&&c.len>1;c.len--);

		return c;

	}

	void initialize(char *s){

		int l=strlen(s+1);

		for (int i=l;i>=1;i-=8){

			len++;int x=pow(10,min(i-1,7)),t=max(i-8+1,1);

			while (x) a[len]+=(s[t]-'0')*x,t++,x/=10;

		}

	}

	void print(){

		printf("%d",a[len]);

		for (int i=len-1;i;i--) printf("%08d",a[i]);

	}

}f[maxn],t;

int main(){

	scanf("%d",&n);f[1].a[1]=1,f[1].len=1,f[2].a[1]=5,f[2].len=1,t.a[1]=2,t.len=1;

	for (int i=3;i<=n;i++) f[i]=f[i-1]+f[i-1]+f[i-1]-f[i-2]+t;

	f[n].print();

	return 0;

}