#include<bits/stdc++.h>
using namespace std;
int t,n,m,ans,t1[8000001],t2[8000001],a[2000001],b[2000001],sa[2000001],sb[2000001],la[2000001],lb[2000001],ra[2000001],rb[2000001];
void add1(int x,int v){for(int i=x+n+m+1;i<=(n+m)*3+1;i+=i&-i) t1[i]=max(t1[i],v);}
void add2(int x,int v){for(int i=x+n+m+1;i>=1;i-=i&-i) t2[i]=max(t2[i],v);}
int ask1(int x){int s=-1e9;for(int i=x+n+m+1;i>=1;i-=i&-i) s=max(s,t1[i]);return s;}
int ask2(int x){int s=-1e9;for(int i=x+n+m+1;i<=(n+m)*3+1;i+=i&-i) s=max(s,t2[i]);return s;}
int main(){
	scanf("%d",&t);
	while(t--){
		scanf("%d%d",&n,&m),ans=0;
        for(int i=-n-m;i<=(n+m)*2;i++) t1[i+n+m+1]=t2[i+n+m+1]=-1e9;
		for(int i=1;i<=n;i++) scanf("%d",&a[i]),sa[i]=sa[i-1]+(a[i]==2);
		for(int i=1;i<=m;i++) scanf("%d",&b[i]),sb[i]=sb[i-1]+(b[i]==2);
        ra[0]=n+1,rb[0]=m+1;
		for(int i=1;i<=n;i++) la[i]=n+1,ra[i]=0;
		for(int i=1;i<=m;i++) lb[i]=m+1,rb[i]=0;
		for(int i=1,j=0;i<=n;i++) if(a[i]==1) la[++j]=i;
		for(int i=n,j=0;i>=1;i--) if(a[i]==3) ra[++j]=i;
		for(int i=1,j=0;i<=m;i++) if(b[i]==1) lb[++j]=i;
		for(int i=m,j=0;i>=1;i--) if(b[i]==3) rb[++j]=i;
		for(int i=min(n,m),j=0;i>=0;i--){
			while(j<=min(n,m)&&la[i]<ra[j]&&lb[i]<rb[j]) add1(sa[ra[j]-1]-sb[rb[j]-1],j+sa[ra[j]-1]),add2(sa[ra[j]-1]-sb[rb[j]-1],j+sb[rb[j]-1]),j++;
            ans=max({ans,ask1(sa[la[i]]-sb[lb[i]])+i-sa[la[i]],ask2(sa[la[i]]-sb[lb[i]])+i-sb[lb[i]]});
		}
		printf("%d\n",ans);
	}
	return 0;
}