- #include <bits/stdc++.h>
- using namespace std;
- int n , t , aux , v[100005];
- int main()
- {
- cin >> n;
- v[0] = 1 , v[1] = 1;
- n = n * (n - 1) / 2;
- while(n)
- {
- t = 0;
- for(int i = 1 ; i <= v[0] ; i++)
- {
- aux = v[i] * 3 + t;
- v[i] = aux % 10;
- t = aux / 10;
- }
- while(t) v[++v[0]] = t % 10 , t /= 10;
- n--;
- }
- for(int i = v[0] ; i ; i--)
- cout << v[i];
- return 0;
- }