#include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long LL; const int matMX = 128 + 5; const int INF = 0x3f3f3f3f; const LL mod = 1e9 + 7; struct Mat { int m, n; LL S[matMX][matMX]; Mat(int a, int b) { m = a; n = b; memset(S, 0, sizeof(S)); } Mat(int a, int b, LL w[][matMX]) { m = a; n = b; for(int i = 0; i < m; i++) { for(int j = 0; j < n; j++) { S[i][j] = w[i][j]; } } } }; Mat mat_mul(Mat A, Mat B) { Mat C(A.m, B.n); for(int i = 0; i < A.m; i++) { for(int j = 0; j < B.n; j++) { for(int k = 0; k < A.n; k++) { C.S[i][j] = (C.S[i][j] + A.S[i][k] * B.S[k][j]) % mod; } } } return C; } Mat Blank(int m, int n) { Mat ret(m, n); for(int i = 0; i < m; i++) { ret.S[i][i] = 1; } return ret; } Mat mat_pow(Mat A, LL b) { Mat ret = Blank(A.m, A.n); while(b) { if(b & 1) ret = mat_mul(ret, A); A = mat_mul(A, A); b >>= 1; } return ret; } LL S[matMX][matMX]; void DFS(int m, int cnt, int x, int y) { if(cnt == m) { S[x][y] = 1; return; } DFS(m, cnt + 1, x << 1, y << 1); DFS(m, cnt + 1, x << 1 | 1, y << 1 | 1); if(cnt) { if((x & 1) ^ (y & 1) == 0) { DFS(m, cnt + 1, x << 1, y << 1 | 1); DFS(m, cnt + 1, x << 1 | 1, y << 1); } else if((x & 1) && !(y & 1)) { DFS(m, cnt + 1, x << 1 | 1, y << 1); } else { DFS(m, cnt + 1, x << 1, y << 1 | 1); } } else { DFS(m, cnt + 1, x << 1 | 1, y << 1); DFS(m, cnt + 1, x << 1, y << 1 | 1); } } int main() { int m, n; while(~scanf("%d%d", &n, &m)) { DFS(m, 0, 0, 0); Mat A(1 << m, 1 << m, S), B(1 << m, 1); memset(B.S, 0, sizeof(B.S)); B.S[0][0] = 1; Mat ret = mat_mul(mat_pow(A, n), B); LL ans = 0; for(int i = 0; i < (1 << m); i++) { ans += ret.S[i][0]; ans %= mod; } printf("%I64d\n", ans); } return 0; }