#include<bits/stdc++.h>
using namespace std;
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define ll long long
#define INF 9999999999999999
#define rep(i,m,n) for(ll i = m;i < n;i++)
#define rrep(i,m,n) for(ll i = m - 1; i >= n; i--)
#define pb(n) push_back(n)
#define UE(N) N.erase(unique(N.begin(), N.end()), N.end());
#define Sort(n) sort(n.begin(), n.end())
#define Rev(n) reverse(n.begin(), n.end())
#define Out(S) cout << S << endl
#define NeOut(S) cout << S
#define HpOut(S) cout << setprecision(50) << S << endl
#define Vec(K,L,N,S) vector<L> K(N,S)
#define DV(K,L,N,M,S) vector<vector<L>> K(N,vector<L>(M,S))
#define TV(K,L,N,M,R,S) vector<vector<vector<L>>> K(N,vector<vector<L>>(M,vector<L>(R,S)))
#define pint pair<ll,ll>
#define tint tuple<ll, ll, ll>
#define mod 998244353
#define MAX 100010
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))

int main() {
    ll N;
    cin >> N;
    vector<ll> A(N), B(N);
    rep(i, 0, N) cin >> A[i];
    rep(i, 0, N) cin >> B[i];
    Sort(A);
    multimap<ll, ll> mp;
    mp.insert(pint(0, 0));
    ll res = 0;
    rep(i, 0, N) {
        mp.insert(pint(B[i], 0));
        auto itr = mp.lower_bound(A[i]);
        itr--;
        //res += distance(mp.begin(), itr);
        //cout << *itr << " " << res << endl;
    }
    cout << res << endl;
}