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#include <iostream>
#include <vector>
#include <deque>

typedef long long ll;

ll vector_sum(const std::vector<ll>& v, ll p) {
  ll total = 0;
  for (auto value : v) {
    total = (total + value) % p;
  }
  return total;
}

int main() {
  ll l, h, p;
  std::cin >> l >> h >> p;

  std::vector<ll> starts;
  std::vector<ll> new_beginnings;
  starts.resize(h);
  new_beginnings.resize(h);

  for (ll i = 0; i < h; ++i) {
    new_beginnings[i] = (h - i) % p;
  }

  for (int i = 1; i < l; ++i) {
    std::deque<ll> running_sums;
    new_beginnings.swap(starts);
    ll running_sum = 0;
    ll grand_total = 0;
    for (int i = 0; i < h; i++) {
      running_sum += starts[i];
      running_sum %= p;
      running_sums.push_back(running_sum);
      grand_total += running_sum;
      grand_total %= p;
    }

    ll loss = 0;
    for (int i = 0; i < h; i++) {
      new_beginnings[i] = grand_total;
      grand_total += loss - running_sums.front();
      running_sums.pop_front();
      loss += starts[h - i - 1];
      ll gt_loss = starts[h - i - 1] * running_sums.size() % p;
      grand_total -= gt_loss;
      grand_total %= p;
      grand_total += p;
      grand_total %= p;
    }
  }

  std::cout << vector_sum(new_beginnings, p) << std::endl;

  return 0;
}