#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("Ofast,unroll-loops,inline-functions,no-stack-protector,03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#pragma clang loop vectorize(enable)
#pragma clang loop interleave(enable)
#define int long long
#define sz(x) (int)x.size()
#define F first
#define S second
#define pb push_back
#define nl '\n'
#define o_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef pair<int, int> pii;
void file( string s = "" )
{
if( s.empty() )
return;
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
const int N = 2e5 + 2;
const int N1 = 1e6 + 2;
const int inf = 1e9 + 2;
const int INF = 1e18 + 2;
const int mod = 1e9 + 7;
int T = 1, n, a[N], b[N], t[N];
void upd( int i, int x )
{
for( ; i < N; i += i & -i )
t[i] = max(t[i], x);
}
int get( int i )
{
int res = 0;
for( ; i > 0; i -= i & -i )
res = max(res, t[i]);
return res;
}
void solve()
{
cin >>n;
int cnt = 0;
vector< int > l(n + 1, 1), r(n + 1, n);
stack< int > st;
set< int > stt;
for( int i = 1; i <= n; ++i )
{
cin >>a[i];
stt.insert(a[i]);
}
for( int i = 1; i <= n; ++i )
{
while( !st.empty() && a[st.top()] <= b[i] )
st.pop();
if( !st.empty() )
l[i] = st.top() + 1;
st.push(i);
}
while( !st.empty() )
st.pop();
for( int i = n; i >= 1; --i )
{
while( !st.empty() && a[st.top()] <= b[i] )
st.pop();
if( !st.empty() )
r[i] = st.top() - 1;
st.push(i);
}
for( int i = 1; i <= n; ++i )
{
cin >>b[i];
if( b[i] == b[1] )
++cnt;
}
if( cnt == n )
{
int ans = 0;
int ch = 0, c = 0;
for( int i = 1; i <= n; ++i )
{
if( a[i] > b[1] )
{
ans += ch * c;
c = ch = 0;
continue;
}
++c;
if( a[i] == b[1] )
ch = 1;
}
ans += c * ch;
cout <<ans;
return;
}
if( sz(stt) == n )
{
int ans = 0;
map<int, int> pos;
for( int i = 1; i <= n; ++i )
pos[a[i]] = i;
for( int j = 1; j <= n; ++j )
{
if( !pos.count(b[j]) )
continue;
int i = pos[b[j]];
if( l[i] <= j && j <= r[i] )
{
int x = get(i) + 1;
upd(i, 1);
ans = max(ans, x);
}
}
cout <<ans;
return;
}
}
signed main()
{
file("");
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// cin >>T;
while( T-- )
solve();
}
