#include <bits/stdc++.h> typedef long long ll; #define pb push_back #define MS(x,y) memset((x),(y),sizeof((x))) #define MN 1000000007 using namespace std; const int MAXN = 1001; vector<int> frames; vector<pair<int,int>> pics; int n,m; int dp[MAXN][MAXN]; int rec(int posP, int posF) { if (posP >= n || posF >= m) return 0; if (dp[posP][posF] != -1) return dp[posP][posF]; int ret = rec(posP+1,posF); int org = posF; for (; posF<m; posF++) { if (frames[posF] >= pics[posP].second) { ret = max(ret,rec(posP+1,posF+1)+1); break; } } return dp[posP][org] = ret; } int main() { #if LOCAL_DEBUG fstream cin("in.txt"); #endif ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); MS(dp,-1); cin>>n>>m; pics.resize(n); for (int i = 0; i<n; i++) cin>>pics[i].second>>pics[i].first; sort(pics.begin(),pics.end()); frames.resize(m); for (int i = 0; i<m; i++) cin>>frames[i]; sort(frames.begin(),frames.end()); cout<<rec(0,0)<<endl; return 0; }