#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
const int MAXN=510;
int uN,vN;//u,v数目
int g[MAXN][MAXN];
int linker[MAXN];
bool used[MAXN];
bool dfs(int u)//从左边开始找增广路径
{int v;for(v=0;v<vN;v++)//这个顶点编号从0开始，若要从1开始需要修改if(g[u][v]&&!used[v]){used[v]=true;if(linker[v]==-1||dfs(linker[v])){//找增广路，反向linker[v]=u;return true;}}return false;//这个不要忘了，经常忘记这句
}
int hungary()
{int res=0;int u;memset(linker,-1,sizeof(linker));for(u=0;u<uN;u++){memset(used,0,sizeof(used));if(dfs(u)) res++;}return res;
}

#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
const int MAXN=510;
int uN,vN;//u,v数目
int g[MAXN][MAXN];
int linker[MAXN];
bool used[MAXN];
bool dfs(int u)//从左边开始找增广路径
{int v;for(v=0;v<vN;v++)//这个顶点编号从0开始，若要从1开始需要修改if(g[u][v]&&!used[v]){used[v]=true;if(linker[v]==-1||dfs(linker[v])){//找增广路，反向linker[v]=u;return true;}}return false;//这个不要忘了，经常忘记这句
}
int hungary()
{int res=0;int u;memset(linker,-1,sizeof(linker));for(u=0;u<uN;u++){memset(used,0,sizeof(used));if(dfs(u)) res++;}return res;
}
int main()
{memset(g,0,sizeof(g));int b[MAXN],g1[MAXN];cin>>uN;for(int i=0;i<uN;i++)cin>>b[i];cin>>vN;for(int i=0;i<vN;i++)cin>>g1[i];for(int i=0;i<uN;i++){for(int j=0;j<vN;j++){if(fabs(b[i]-g1[j])<=1)g[i][j]=1;}}cout<<hungary()<<endl;return 0;
}