// -*- coding:utf-8-unix -*- #![allow(dead_code)] #![allow(unused_imports)] use std::cmp::Ordering::*; use std::collections::*; use std::convert::*; use std::convert::{From, Into}; use std::fmt::Debug; use std::fs::File; use std::io::prelude::*; use std::io::*; use std::marker::Copy; use std::mem::*; use std::ops::Bound::*; use std::ops::{Add, Mul, Neg, Sub}; use std::str; use std::vec; use std::{cmp, process::Output}; use std::{cmp::Ordering, env::consts::DLL_PREFIX}; const INF: i64 = 1223372036854775807; const MEM_SIZE: usize = 202020; const MOD: i64 = 1000000007; // const MOD: i64 = 998244353; use std::cmp::*; use std::collections::*; use std::io::stdin; use std::io::stdout; use std::io::Write; use btree_map::{Keys, Values}; // use str::Chars; #[allow(dead_code)] fn read() -> T { let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); s.trim().parse().ok().unwrap() } #[allow(dead_code)] fn readi() -> (i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); iter.next().unwrap().parse::().unwrap() } #[allow(dead_code)] fn read_vec() -> Vec { read::() .split_whitespace() .map(|e| e.parse().ok().unwrap()) .collect() } #[allow(dead_code)] fn read_vec2(n: u32) -> Vec> { (0..n).map(|_| read_vec()).collect() } #[allow(dead_code)] fn readii() -> (i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readff() -> (f64, f64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readiii() -> (i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuu() -> (usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readcc() -> (char, char) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuuu() -> (usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuuuu() -> (usize, usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readiiii() -> (i64, i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readin() -> (usize, char) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn solve() { let n: usize = read(); let vec: Vec = read_vec(); let mut dp = vec![0; n + 1]; dp[0] = 1; let m = (n as f64).sqrt() as usize; let mut sum = vec![vec![0 as usize; (m + 1) as usize]; (m + 1) as usize]; for i in 0..n { if i != 0 { if vec[i - 1] > 1 { dp[i] += dp[i - 1]; dp[i] %= MOD as usize; } } for j in 1..=m { dp[i] += sum[j][i % j]; dp[i] %= MOD as usize; } if vec[i] <= m { sum[vec[i]][i % vec[i]] += dp[i]; sum[vec[i]][i % vec[i]] %= MOD as usize; } else { let mut p = i + vec[i]; while p < n { dp[p] += dp[i]; dp[p] %= MOD as usize; p += vec[i]; } } } // println!("{:?}", dp); println!("{:?}", dp[n - 1]); return; } fn main() { solve() }