#include using namespace std; typedef long long ll; typedef long double ld; #define all(x) (x).begin(),(x).end() const int mod=1000000007,MAX=100001,INF=1<<30; int main(){ int N;cin>>N; vector A(N+1),B(N+1),S(N+1,0); for(int i=0;i>A[i]; } for(int i=0;i>B[i]; if(i) S[i]=(S[i-1]+B[i])%mod; else S[i]=B[i]; } ll ans=0; for(int i=0;i