题解 | #Let'sPlayCurling#

#include<bits/stdc++.h>

using namespace std;

map<int,int> mp;
map<int,int> cnt;

int T,n,m;

int main()
{
    cin >> T;
    while(T--){
        mp.clear();
        cnt.clear();
        cin >> n >> m;
        int i,x;
        for(i=1;i<=n;i++){
            scanf("%d",&x);
            mp[x]=1;
            cnt[x]++;
        }
        for(i=n+1;i<=n+m;i++){
            scanf("%d",&x);
            mp[x]=2;
            cnt[x]=0;
        }
        int tmp=0,ans=0;
        for(auto &it:mp){
            if(it.second==2){
                tmp=0;
            }else{
                tmp+=cnt[it.first];
            }
            ans=max(ans,tmp);
        }
        if(ans == 0){
            printf("Impossible\n");
        }else{
            printf("%d\n",ans);
        }
    }
}