#pragma GCC optimize ("O3") #pragma GCC target ("avx") #include "bits/stdc++.h" // define macro "/D__MAI" using namespace std; typedef long long int ll; #define debugv(v) printf("L%d %s => ",__LINE__,#v);for(auto e:v){cout< ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout< ostream& operator <<(ostream &o, const pair p) { o << "(" << p.first << ":" << p.second << ")"; return o; } #define TIME chrono::system_clock::now() #define MILLISEC(t) (chrono::duration_cast(t).count()) namespace { std::chrono::system_clock::time_point ttt; void tic() { ttt = TIME; } void toc() { fprintf(stderr, "TIME : %lldms\n", MILLISEC(TIME - ttt)); } std::chrono::system_clock::time_point tle = TIME; #ifdef __MAI void safe_tle(int msec) { assert(MILLISEC(TIME - tle) < msec); } #else #define safe_tle(k) ; #endif } #ifdef __MAI #define getchar_unlocked getchar #define putchar_unlocked putchar #endif #ifdef __VSCC #define getchar_unlocked _getchar_nolock #define putchar_unlocked _putchar_nolock #endif namespace { #define isvisiablechar(c) (0x21<=(c)&&(c)<=0x7E) class MaiScanner { public: template void input_integer(T& var) { var = 0; T sign = 1; int cc = getchar_unlocked(); for (; cc<'0' || '9'>(int& var) { input_integer(var); return *this; } inline MaiScanner& operator>>(long long& var) { input_integer(var); return *this; } inline MaiScanner& operator>>(string& var) { int cc = getchar_unlocked(); for (; !isvisiablechar(cc); cc = getchar_unlocked()); for (; isvisiablechar(cc); cc = getchar_unlocked()) var.push_back(cc); } }; } MaiScanner scanner; int cap, n; int aa[110]; int dp[100010]; constexpr int inf = 1e9; int main() { scanner >> cap >> n; repeat(n) { scanner >> aa[cnt]; } fill(dp, dp + cap + 1, inf); // first for (int i = 0; i < n; ++i) { dp[aa[i]] = 1; } for (int i = 0; i < n; ++i) { for (int w = 1; w <= cap - aa[i]; ++w) { dp[w + aa[i]] = min(dp[w] + 1, dp[w + aa[i]]); } } cout << (dp[cap]!= inf ? dp[cap] : -1) << endl; return 0; }