func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 5003, mod = 1e9 + 7;   long long n, k, S[N][N], ans;   inline long long kasumi(long long a, long long b) {     long long res = 1;     while (b) {       if (b & 1) res = (long long)res * a % mod;       a = (long long)a * a % mod;       b >>= 1;     }     return res;   }   signed main() {     scanf( %d%d , &n, &k);     S[0][0] = 1;     for (register long long i = 1; i <= k; i++)       for (register long long j = 1; j <= i; j++)         S[i][j] = ((long long)S[i - 1][j] * j + S[i - 1][j - 1]) % mod;     long long fac = 1, cho = 1;     for (register long long i = 1; i <= k && i <= n; i++) {       cho = (long long)cho * (n - i + 1) % mod * kasumi(i, mod - 2) % mod;       fac = (long long)fac * i % mod;       ans = (ans + (long long)fac * cho % mod * kasumi(2, n - i) % mod * S[k][i] %                        mod) %             mod;     }     printf( %d , ans);   }   