// need #include #include // data structure #include #include #include #include #include #include #include #include #include //#include #include #include // stream //#include //#include //#include #include // etc #include #include #include #include #include #include #include // input #define INIT std::ios::sync_with_stdio(false);std::cin.tie(0); #define VAR(type, ...)type __VA_ARGS__;MACRO_VAR_Scan(__VA_ARGS__); template void MACRO_VAR_Scan(T& t) { std::cin >> t; } templatevoid MACRO_VAR_Scan(First& first, Rest&...rest) { std::cin >> first; MACRO_VAR_Scan(rest...); } #define VEC_ROW(type, n, ...)std::vector __VA_ARGS__;MACRO_VEC_ROW_Init(n, __VA_ARGS__); for(int i=0; i void MACRO_VEC_ROW_Init(int n, T& t) { t.resize(n); } templatevoid MACRO_VEC_ROW_Init(int n, First& first, Rest&...rest) { first.resize(n); MACRO_VEC_ROW_Init(n, rest...); } template void MACRO_VEC_ROW_Scan(int p, T& t) { std::cin >> t[p]; } templatevoid MACRO_VEC_ROW_Scan(int p, First& first, Rest&...rest) { std::cin >> first[p]; MACRO_VEC_ROW_Scan(p, rest...); } #define VEC(type, c, n) std::vector c(n);for(auto& i:c)std::cin>>i; #define MAT(type, c, m, n) std::vector> c(m, std::vector(n));for(auto& r:c)for(auto& i:r)std::cin>>i; // output #define OUT(d) std::cout<<(d); #define FOUT(n, d) std::cout<=(a);--i) #define REP(i, n) for(int i=0;i=0;--i) #define FORLL(i, a, b) for(ll i=ll(a);i=ll(a);--i) #define REPLL(i, n) for(ll i=0;i=0;--i) #define IN(a, x, b) (a<=x && x inline T CHMAX(T& a, const T b) { return a = (a < b) ? b : a; } template inline T CHMIN(T& a, const T b) { return a = (a > b) ? b : a; } #define EXCEPTION(msg) throw std::string("Exception : " msg " [ in ") + __func__ + " : " + std::to_string(__LINE__) + " lines ]" #define TRY(cond, msg) try {if (cond) EXCEPTION(msg);}catch (std::string s) {std::cerr << s << std::endl;} void CHECKTIME(std::function f) { auto start = std::chrono::system_clock::now(); f(); auto end = std::chrono::system_clock::now(); auto res = std::chrono::duration_cast((end - start)).count(); std::cerr << "[Time:" << res << "ns (" << res / (1.0e9) << "s)]\n"; } // test template std::vector> VV(int n, int m, T init = T()) { return std::vector>(n, std::vector(m, init)); } template std::ostream& operator<<(std::ostream& os, std::pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } // type/const //#define int ll using ll = long long; using ull = unsigned long long; using ld = long double; using PAIR = std::pair; using PAIRLL = std::pair; constexpr int INFINT = 1 << 30; // 1.07x10^ 9 constexpr int INFINT_LIM = (1LL << 31) - 1; // 2.15x10^ 9 constexpr ll INFLL = 1LL << 60; // 1.15x10^18 constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62); // 9.22x10^18 constexpr double EPS = 1e-9; constexpr int MOD = 1000000007; constexpr double PI = 3.141592653589793238462643383279; template void FILL(T(&a)[N], const T& val) { for (auto& x : a) x = val; } template void FILL(ARY(&a)[N][M], const T& val) { for (auto& b : a) FILL(b, val); } template void FILL(std::vector& a, const T& val) { for (auto& x : a) x = val; } template void FILL(std::vector>& a, const T& val) { for (auto& b : a) FILL(b, val); } // ------------>8------------------------------------->8------------ ll powMod(ll n, ll p, ll mod) { ll res = 1; while (p) { if (p & 1) (res *= n) %= mod; (n *= n) %= mod; p >>= 1; } return res; } std::map inv; ll invMod(ll n, ll mod) { if (inv.count(n)) return inv[n]; return inv[n] = powMod(n, mod - 2, mod); } constexpr int SZ = 2; constexpr int M[SZ] = { 168647939, 592951213 }; int dp[10000007]; signed main() { INIT; VAR(int, n, m); VEC(int, x, m); auto calc = [&](int MM) { FILL(dp, 0); dp[0] = 1; int res = 0; if (n <= 10000000) { REP(i, n - 1) { if (dp[i] == 0) continue; REP(j, m) { if (i + x[j] >= n) continue; (dp[i + x[j]] += dp[i]) %= MM; } } res = dp[n - 1]; } else { int n2 = n / 2 + 1; REP(i, n2 - 1) { if (dp[i] == 0) continue; REP(j, m) { if (i + x[j] >= n) continue; (dp[i + x[j]] += dp[i]) %= MM; } } REP(i, n2) { REP(j, m) { if (i + x[j] >= n2) { (res += (ll)dp[i] * dp[n - (i + x[j] + 1)] % MM) %= MM; } } } } return res; }; ll a = calc(M[0]); ll b = calc(M[1]); const ll r01 = invMod(M[0], M[1]); b = (b - a) * r01 % M[1]; if (b < 0) b += M[1]; a = (a + b * M[0]) % ((ll)M[0] * M[1]); OUT(a)BR; return 0; }