#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
using namespace std;
const int N = 1e2 + 5;
const ld PI = acos(-1);
int n, m, a[N], b[N];
ld memo[N][N];
ld unit_ang;
ld dis(int i, int j) {
	if(i > j)
		swap(i, j);
	int cnt = min(j - i, m - j + i);
	ld ang = cnt * unit_ang;
	if(ang == 180)
		return 2;
	ld rad = ang * PI / 180;
	ld ret = sin(rad / 2);
	return ret * 2;
}
ld solve(int i, int lst) {
	if(i == n)
		return 0;
	ld &ans = memo[i][lst];
	if(ans != -1)
		return ans;
	ans = 1e9;
	for(int j = 0;j < m;j++) {
		if(b[j] == a[i])
			ans = min(ans, solve(i + 1, j) + dis(lst, j));
	}
	return ans;
}
int main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin >> n;
	for(int i = 0;i < n;i++)
		cin >> a[i];
	cin >> m;
	for(int i = 0;i < m;i++)
		cin >> b[i];
	unit_ang = (ld)360 / (ld)m;
	for(int i = 0;i < N;i++)
		for(int j = 0;j < N;j++)
			memo[i][j] = -1;
	ld ans = 1e9;
	for(int i = 0;i < m;i++)
		if(b[i] == a[0])
			ans = min(ans, solve(1, i) + 1);
	cout << fixed << setprecision(9) << ans;
    return 0;
}