func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mo = 1e9 + 7;   struct node {     int mat[210][210];   } qwq;   int n, k, m;   inline int ha(int x, int y) { return x * (1 << m) + y; }   node ksm(int l) {     if (l == 1) return qwq;     node op = ksm(l / 2), op2;     memset(op2.mat, 0, sizeof(op2.mat));     for (int i = 0; i < (k + 1) * (1 << m); i++)       for (int j = 0; j < (k + 1) * (1 << m); j++)         for (int h = 0; h < (k + 1) * (1 << m); h++)           op2.mat[i][j] =               (op2.mat[i][j] + 1ll * op.mat[i][h] * op.mat[h][j]) % mo;     if (l % 2 == 0) return op2;     node op3;     memset(op3.mat, 0, sizeof(op3.mat));     for (int i = 0; i < (k + 1) * (1 << m); i++)       for (int j = 0; j < (k + 1) * (1 << m); j++)         for (int h = 0; h < (k + 1) * (1 << m); h++)           op3.mat[i][j] =               (op3.mat[i][j] + 1ll * qwq.mat[i][h] * op2.mat[h][j]) % mo;     return op3;   }   int main() {     scanf( %d%d%d , &n, &k, &m);     for (int i = 0; i <= k; i++)       for (int j = 0; j < (1 << m); j++) {         int ovo = (j << 1) % (1 << m);         qwq.mat[ha(i, ovo)][ha(i, j)]++;         if (i > 0) {           int way_to_here = 1;           for (int r = 0; r < m; r++)             if ((1 << r) & j) way_to_here++;           qwq.mat[ha(i, ovo | 1)][ha(i - 1, j)] += way_to_here;         }       }     node uoj = ksm(n);     int ans = 0;     for (int i = 0; i < (1 << m); i++)       ans = (ans + 1ll * uoj.mat[ha(k, i)][0]) % mo;     printf( %d , ans);     return 0;   }   