#include //#include #pragma GCC optimize("Ofast") using namespace std; #define reps(i,s,n) for(int i = s; i < n; i++) #define rep(i,n) reps(i,0,n) #define Rreps(i,n,e) for(int i = n - 1; i >= e; --i) #define Rrep(i,n) Rreps(i,n,0) #define ALL(a) a.begin(), a.end() #define fi first #define se second typedef long long ll; typedef vector vec; typedef vector mat; ll N,M,H,W,Q,K,A,B; string S; typedef pair P; const ll INF = (1LL<<60); int main() { cin>>N; vec a(N), b(N); rep(i,N) cin>>a[i]; rep(i,N) cin>>b[i]; if(a[0] != b[0] || a[N - 1] != b[N - 1]){ cout<<-1< bitree; public: BIT(unsigned long _n) : bitree(_n + 1, 0){ n = _n; } void add(ll id, ll x){ while(id <= n){ bitree[id] += x; id += id & -id; } return; } ll sum(ll id){ ll temp = 0; while(id > 0){ temp += bitree[id]; id -= id & -id; } return temp; } }; unordered_map > b_id; unordered_map id_id; BIT bit(N + 5); ll res(0); rep(i,N) b_id[b[i]].push_back(i + 1); rep(i,N) { int id = b_id[a[i]][id_id[a[i]]++]; res += i - bit.sum(id); bit.add(id, 1); } cout<