t=int(input())
for _ in range(t):
n,m =[int(i) for i in input().split()]
a=[int(i) for i in input().split()]
worker=[0]*n
for x in a:
worker[x-1]+=1
high=max(worker)
low=0
while low<=high:
mid=low+(high-low)//2
tasks=0
for x in worker:
if x>=mid:
tasks+=mid
else:
tasks+=x+(mid-x)//2
if tasks>=m:
high=mid-1
else:
low=mid+1
print(low)
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define max1 300021
#define gcd __gcd
const ll mod=1e9+7;
#define NO {puts("NO") ; return ;}
#define YES {puts("YES") ; return ;}
const ll INF = 0x3f3f3f3f;
#define nx x+fx[i][0]
#define ny y+fx[i][1]
#define pb push_back
#define pii pair<int,int>
const ll N=3e5+10;
ll m,ans,k,d,t,c,cnt,n,l,r,i,j;
string strr,str;
ll len=0,gs=0,min_=INF,sum=0;
int max_;
ll fx[4][2]={{1,0},{0,1},{-1,0},{0,-1}};
int t1[max1];
inline ll lowbit(ll x){return x&(-x);}
inline ll ls(ll x){return x<<1;}
inline ll rs(ll x){return x<<1|1;}
void update(ll x,ll d){while(x<=n){t1[x]+=d;x+=lowbit(x);}}
inline ll qsum(ll x){ll ans=0;while(x>0){ans+=t1[x];x-=lowbit(x);}return ans;}
struct edge{
int u,v,w,nex;
}e[max1];
struct node{
int u,val;
};
ll head[max1],a[max1],s[max1],in[max1],dp[205][205];
int st,ed;
void add(int x,int y,int z)
{
e[++cnt].u=x;
e[cnt].v=y;
e[cnt].w=z;
e[cnt].nex=head[x];
head[x]=cnt;
}
inline void solve() {
cin>>n>>m;ans=1;
fill(a+1,a+n+1,0);
for(int i=1;i<=m;i++) cin>>c,a[c]++;
// sort(s+1,s+n+1);
int l=1,r=m*2;
// cout<<r<<"\n";
auto check = [&](int t) {
int64_t r = m;
for (int i = 1;i <= n;i++) {
if (a[i] < t) r -= a[i] + (t - a[i]) / 2;
else r -= t;
}
return r <= 0;
};
while(l<r){
int mid=(l+r)/2;
if(check(mid)) r=mid;
else l=mid+1;
// cout<<r<<endl;
}
cout<<l<<"\n";
}
int main() {
cin.tie(nullptr) -> sync_with_stdio(false);
cout.tie(0);cout.setf(ios::fixed);
int __=1;
cin>>__;
while(__--)
{
solve();
}
return 0;
}1609A - Divide and Multiply | 149B - Martian Clock |
205A - Little Elephant and Rozdil | 1609B - William the Vigilant |
978B - File Name | 1426B - Symmetric Matrix |
732B - Cormen --- The Best Friend Of a Man | 1369A - FashionabLee |
1474B - Different Divisors | 1632B - Roof Construction |
388A - Fox and Box Accumulation | 451A - Game With Sticks |
768A - Oath of the Night's Watch | 156C - Cipher |
545D - Queue | 459B - Pashmak and Flowers |
1538A - Stone Game | 1454C - Sequence Transformation |
165B - Burning Midnight Oil | 17A - Noldbach problem |
1350A - Orac and Factors | 1373A - Donut Shops |
26A - Almost Prime | 1656E - Equal Tree Sums |
1656B - Subtract Operation | 1656A - Good Pairs |
1367A - Short Substrings | 87A - Trains |
664A - Complicated GCD | 1635D - Infinite Set |