#include #include #include #include #include #include #include #include #include #include #include using namespace std; #define N (1000000000+7) //#define N (998244353) #define INF 1e16 typedef long long ll; typedef pair P; ll kaijo[200010]; void init() { kaijo[0] = 1; for (ll i = 1;i <= 200000;i++)kaijo[i] = (kaijo[i - 1] * i) % N; } ll inv(ll x,ll power) { ll res = 1; ll k = power; ll y = x%N; while (k) { if (k & 1)res = (res*y) % N; y = (y%N*y%N) % N; k /= 2; } return res; } ll Comb(ll n, ll k) { if (n < 0 || k < 0 || (n - k) < 0)return 0; ll b = kaijo[n]; ll c = kaijo[n - k]; ll d = kaijo[k]; ll cd = (c*d) % N; return ((b%N)*(inv(cd,N-2)) % N) % N; } int main(void){ init(); ll n; cin>>n; vectora(n); for(int i=0;i>a[i]; ll ans = 0; for(ll i=0;i