#include<bits/stdc++.h> using namespace std; int N=7e4; uint64_t s = N, t = 0; uint64_t next() { s ^= (s << 13); s ^= (s >> 7); s ^= (s << 17); return s; } int main(){ int n;cin>>n; if(n!=5) return 0; vector <uint64_t> vec(N); uint64_t cnt = 0; for (int i = 0; i < N; ++i) vec[i] = next(); for (int i = 0; i < N - 1; ++i) { for (int j = i + 1; j < N; j++) if (vec[i] > vec[j]) cnt++; } cout << cnt << endl; }