// IOI 2021
#include <bits/stdc++.h>
using namespace std;
 
#define endl '\n'
#define ends ' '
#define die(x) return cout << x << endl, 0
#define all(v) v.begin(), v.end()
#define sz(x) (int)(x.size())
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) { cerr << ends << H; debug_out(T...); }
#define debug(...) cerr << "{" << #__VA_ARGS__ << "}:", debug_out(__VA_ARGS__)
typedef long long ll;
typedef pair<int, int> pii;
const int INF = 1e9;
//const ll MOD = 998244353;
 
////////////////////////////////////////////////////////////////////
 
const int N = 5e3 + 5;

int DP[N];

int main() {
 
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	mt19937 Rnd(time(0));

	int n, MOD; cin >> n >> MOD;
	DP[0] = 1;
	for (int i = 1; i < n; i++) {
		int z = min(i, n - i + 1);
		for (int j = z; j < n; j++) DP[j] = (DP[j] + DP[j - z]) % MOD;
	}
	int ans = 0;
	for (int i = 0; i < n; i++) ans = (ans + 1LL * (n - i) * DP[i]) % MOD;
	cout << ans << endl;

	return 0;
}
