#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<string>
#include<iostream>
#include<sstream>
#include<set>
#include<map>
#include<queue>
#include<bitset>
#include<vector>
#define SZ(X) ((int)(X).size())
#define ALL(X) (X).begin(), (X).end()
#define REP(I, N) for (int I = 0; I < (N); ++I)
#define REPP(I, A, B) for (int I = (A); I < (B); ++I)
#define RI(X) scanf("%d", &(X))
#define RII(X, Y) scanf("%d%d", &(X), &(Y))
#define RIII(X, Y, Z) scanf("%d%d%d", &(X), &(Y), &(Z))
#define DRI(X) int (X); scanf("%d", &X)
#define DRII(X, Y) int X, Y; scanf("%d%d", &X, &Y)
#define DRIII(X, Y, Z) int X, Y, Z; scanf("%d%d%d", &X, &Y, &Z)
#define RS(X) scanf("%s", (X))
#define CASET int ___T, case_n = 1; scanf("%d ", &___T); while (___T-- > 0)
#define MP make_pair
#define PB push_back
#define MS0(X) memset((X), 0, sizeof((X)))
#define MS1(X) memset((X), -1, sizeof((X)))
#define LEN(X) strlen(X)
#define PII pair<int,int>
#define VI vector<int>
#define VPII vector<pair<int,int> >
#define PLL pair<long long,long long>
#define VPLL vector<pair<long long,long long> >
#define F first
#define S second
typedef long long LL;
using namespace std;
const int MOD = 1e9+7;
const int SIZE = 2e3+10;
long double dp[SIZE];
int a[SIZE];
long double v[SIZE];
int main(){
    v[1]=0;
    REPP(i,2,SIZE)v[i]=log2(i);
    CASET{
        DRII(N,M);
        REP(i,M)RI(a[i]);
        if(M==1){
            printf("%.0f\n",(double)floor(v[N]*1000000));
            continue;
        }
        sort(a,a+M);
        {
            int bb=min(N,a[1]);
            REPP(i,a[0],bb)dp[i]=v[i+1];
        }
        a[M]=N;
        REPP(i,1,M){
            REPP(j,a[i],a[i+1]){
                dp[j]=0;
                REPP(k,a[i-1],a[i]){
                    dp[j]=max(dp[j],dp[k]+v[j-k]);
                }
            }
        }
        printf("%.0f\n",(double)floor(dp[N-1]*1000000));
    }
    return 0;
}