#include <iostream>
#include <vector>

using namespace std;

int score(int a, int b) {
  int d = abs(a-b);
  if(d <= 15) return 7;
  if(d <= 23) return 6;
  if(d <= 43) return 4;
  if(d <= 102) return 2;
  return 0;
}
int main() {
  int n, m;
  cin >> n >> m;
  vector<vector<int>> dp(n+1);
  for(auto& x: dp) x.resize(m+1);
  vector<int> expectedv(n), actualv(m);
  for(auto& x: expectedv) cin >> x;
  for(auto& x: actualv) cin >> x;
  for(int i = 0; i <= n; i++) {
    for(int j = 0; j <= m; j++) {
      if(i < n) dp[i+1][j] = max(dp[i+1][j], dp[i][j]);
      if(j < m) dp[i][j+1] = max(dp[i][j+1], dp[i][j]);
      if(i < n && j < m) dp[i+1][j+1] = max(dp[i+1][j+1], dp[i][j] + score(expectedv[i], actualv[j]));
    }
  }
  cout << dp[n][m] << "\n";
}