#include<bits/stdc++.h>
using namespace std;
const int MOD = 1e9+7;
const unsigned long long N = 1e5+5;
unsigned long long lgcput(unsigned long long b,unsigned long long p){
unsigned long long a = 1;
while(p){
if(p & 1){
a *= b;
a%=MOD;
}
b*=b;
b%=MOD;
p/=2;
}
return a;
}
unsigned long long cost(unsigned long long n){
return ((unsigned long long)(((unsigned long long)(n *(n+1)))%MOD) *(lgcput(2,MOD-2) % MOD)) %MOD ;
}
struct drept{
unsigned long long h,w;
};
drept v[N];
unsigned long long stk[N];
unsigned long long nwc[N];
int main()
{
//freopen(".in","r",stdin);
ios::sync_with_stdio(false);
cin.tie(0),cout.tie(0);
unsigned long long n;
cin>>n;
for(unsigned long long i =1;i<=n;i++){
cin>>v[i].h;
}
for(unsigned long long i=1;i<=n;i++){
cin>>v[i].w;
}
unsigned long long ans = 0;
unsigned long long nw = 0;
unsigned long long vf = 0;
nwc[0] = 0;
for(unsigned long long i=1;i<=n;i++){
unsigned long long dlted = 0;
while(vf>0 && v[stk[vf]].h >= v[i].h){
dlted += v[stk[vf]].w;
dlted %= MOD;
v[i].w %=MOD;
vf--;
}
nw = ((unsigned long long)nwc[stk[vf]] + ((unsigned long long)cost(v[i].h) * dlted)%MOD ) %MOD;
ans += ((unsigned long long) nw * v[i].w)%MOD;
ans %= MOD;
ans += ((unsigned long long)cost(v[i].h) * cost(v[i].w)) % MOD;
ans %= MOD;
nw += ((unsigned long long) cost(v[i].h) * v[i].w) % MOD;
nw %= MOD;
nwc[i] = nw;
stk[++vf] = i;
v[i].w += dlted;
v[i].w%=MOD;
}
cout<<ans;
return 0;
}
