#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>
const int inf = 2e18,N = 5e5+1,MOD = 1e9+7;
int add(int x,int y) {
x%=MOD;
y%=MOD;
return ((x+y >= MOD) ? (x+y-MOD) : x+y);
}
int mult(int x,int y) {
return ((x%MOD)*(y%MOD))%MOD;
}
int sub(int x,int y) {
y%=MOD;
x%=MOD;
if (x < y) return (MOD+x)-y;
return x-y;
}
void solve() {
int n;
cin >> n;
int h[n+1],w[n+1];
for (int i=1;i<=n;i++) cin >> h[i];
for (int i=1;i<=n;i++) cin >> w[i];
int L[n+1],R[n+1];
vi stk;
for (int i=1;i<=n;i++) {
while (!stk.empty() && h[stk.back()] >= h[i]) stk.pop_back();
if (stk.empty()) L[i] = 1;
else L[i] = stk.back()+1;
stk.push_back(i);
}
stk.clear();
for (int i = n;i>=1;i--) {
while (!stk.empty() && h[stk.back()] > h[i]) stk.pop_back();
if (stk.empty()) R[i] = n;
else R[i] = stk.back()-1;
stk.push_back(i);
}
vi pref(n+1,0);
for (int i=1;i<=n;i++) pref[i] = pref[i-1]+w[i];
int ans = 0,anss = 0;
for (int i=1;i<=n;i++) {
ans = 0;
int tot = sub(pref[R[i]],pref[L[i]-1]);
ans = add(ans,(tot*(tot+1)/2));
int left = sub(pref[i-1],pref[L[i]-1]);
ans = sub(ans,(left*(left+1)/2));
int right = sub(pref[R[i]],pref[i]);
ans = sub(ans,(right*(right+1)/2));
ans = mult(ans,h[i]*(h[i]+1)/2);
anss = add(anss,ans);
}
cout << anss << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
