#include <algorithm>
#include <bits/stdc++.h>
#include <vector>
using namespace std;
#ifndef LOCAL
#define cerr if(false) cerr
#endif
#define out( x ) #x << " = " << x << " "
#define endl "\n"
template<class T, class T2> inline bool chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline bool chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
typedef long long ll;
const ll mod = 1e9 +7;
const int MAX_N = 1e6 + 42;
int main(){
#ifndef LOCAL
std::ios_base::sync_with_stdio( false ); std::cin.tie( NULL ); std::cout.tie( NULL );
#endif
int n;
std::cin >> n;
std::vector< int > a( n );
std::vector< int > d( n );
std::vector< int > e( n );
for( auto& j : a ) std::cin >> j;
for( auto& j : d ) std::cin >> j;
for( auto& j : e ) std::cin >> j;
std::sort( d.begin(), d.end() );
std::sort( e.begin(), e.end() );
cerr << " e " << endl;
for( auto j : e ) cerr << j << " ";
cerr << " d " << endl;
for( auto j : d ) cerr << j << " ";
cerr << endl << endl;
int ind = 0;
ll nas = 0;
for( int i=0 ; i < n ; i++ ){
while( ind < n and e[ind] <= d[i] ) ind ++;
cerr << out( e[ind] ) << out( d[i] ) << out( ind ) << endl;
if( ind == n ) break;
nas ++;
ind ++;
}
std::cout << nas << endl;
return 0;
}
