#include <bits/stdc++.h>
using namespace std;
 
int main()
{
    int n,m,p;
    int l[100000 + 5],r[100000 + 5],x[100000 + 5];
    int s[1000000 + 5];// 1e6 + 5
    cin>>n>>m>>p;
    for(int i = 1; i <= m; i ++)cin>>l[i]>>r[i];
    for(int i = 1; i <= p; i ++)cin>>x[i];
 
    for(int i = 1; i <= p; i ++)s[x[i]] ++;
    for(int i = 1; i <= n; i ++)s[i] = s[i-1] + s[i];
 
    int ans = 0;
    for(int i = 1; i <= m; i ++)if(s[r[i]] - s[l[i] - 1] == 0)ans++;
    cout<<ans;
 
    return 0 ;
}
 

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