#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define rep(i,n) for (int i = 0; i < n; i++)
signed main() {
int n, m, ans=0;
cin >> n >> m;
vector<int> a(n);
vector<int> b(m);
rep(i,n){
cin>>a[i];
}
rep(i,m){
cin>>b[i];
}
set<int>s;
for(int i=0;i<n;i++){
for(int j=i+1;j<n;j++){
s.insert(a[j]-a[i]);
}
}
for(int i=0;i<m;i++){
for(int j=i+1;j<m;j++){
if(s.find(b[j]-b[i]) != s.end()) {
ans++;
}
}
}
cout<<ans;
return 0;
}
