func_code_string: #include <bits/stdc++.h>   using namespace std;   inline int read() {     char c = getchar();     int x = 0;     bool f = 0;     for (; !isdigit(c); c = getchar()) f ^= !(c ^ 45);     for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);     if (f) x = -x;     return x;   }   int mod;   struct modint {     int x;     modint(int o = 0) { x = o; }     modint &operator=(int o) { return x = o, *this; }     modint &operator+=(modint o) {       return x = x + o.x >= mod ? x + o.x - mod : x + o.x, *this;     }     modint &operator-=(modint o) {       return x = x - o.x < 0 ? x - o.x + mod : x - o.x, *this;     }     modint &operator*=(modint o) { return x = 1ll * x * o.x % mod, *this; }     modint &operator^=(int b) {       modint a = *this, c = 1;       for (; b; b >>= 1, a *= a)         if (b & 1) c *= a;       return x = c.x, *this;     }     modint &operator/=(modint o) { return *this *= o ^= mod - 2; }     modint &operator+=(int o) {       return x = x + o >= mod ? x + o - mod : x + o, *this;     }     modint &operator-=(int o) {       return x = x - o < 0 ? x - o + mod : x - o, *this;     }     modint &operator*=(int o) { return x = 1ll * x * o % mod, *this; }     modint &operator/=(int o) { return *this *= ((modint(o)) ^= mod - 2); }     template <class I>     friend modint operator+(modint a, I b) {       return a += b;     }     template <class I>     friend modint operator-(modint a, I b) {       return a -= b;     }     template <class I>     friend modint operator*(modint a, I b) {       return a *= b;     }     template <class I>     friend modint operator/(modint a, I b) {       return a /= b;     }     friend modint operator^(modint a, int b) { return a ^= b; }     friend bool operator==(modint a, int b) { return a.x == b; }     friend bool operator!=(modint a, int b) { return a.x != b; }     bool operator!() { return !x; }     modint operator-() { return x ? mod - x : 0; }   };   inline modint qpow(modint a, int b) { return a ^ b; }   int n, k;   map<int, int> mp;   modint iv[100005], sum[100005];   void div(int l, int r, int k) {     if (k <= 1 || l == r) return mp[r - l + 1]++, void();     int mid = l + r >> 1;     div(l, mid, k - 1), div(mid + 1, r, k - 1);   }   modint getprob(int x, int y) {     modint res = modint(x) * y;     for (register int i = (1); i <= (x); ++i) res -= 2 * (sum[i + y] - sum[i]);     return res;   }   signed main() {     n = read(), k = read(), mod = read();     iv[1] = 1;     for (register int i = (2); i <= (max(4, n)); ++i)       iv[i] = iv[mod % i] * (mod - mod / i);     for (register int i = (1); i <= (n); ++i) sum[i] = sum[i - 1] + iv[i];     div(1, n, k);     modint res = 0;     for (auto it1 : mp)       for (auto it2 : mp) {         if (it1.first == it2.first) {           int cnt = it1.second, len = it1.first;           res += iv[2] * len * (len - 1) * cnt;           res += modint(cnt) * (cnt - 1) * iv[2] * getprob(len, len);         } else if (it1.first < it2.first) {           int l1 = it1.first, l2 = it2.first, c1 = it1.second, c2 = it2.second;           res += getprob(l1, l2) * c1 * c2;         }       }     res *= iv[2];     cout << res.x;     return 0;   }   