#include using namespace std; using ll = long long; using ull = unsigned long long; #define v(t) vector #define p(t) pair #define p2(t, s) pair #define vp(t) v(p(t)) #define rep(i, n) for (int i=0,i##_len=((int)(n)); i=0; --i) #define rep2r(i, a, n) for (int i=((int)(n)),i##_len=((int)(a)); i>=i##_len; --i) #define repi(itr, c) for (__typeof((c).begin()) itr=(c).begin(); itr!=(c).end(); ++itr) #define repir(itr, c) for (__typeof((c).rbegin()) itr=(c).rbegin(); itr!=(c).rend(); ++itr) #define sz(x) ((int)(x).size()) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define SORT(v, n) sort(v, v+n); #define VSORT(v) sort(v.begin(), v.end()); #define RSORT(x) sort(rall(x)); #define pb push_back #define eb emplace_back #define INF (1e9) #define LINF (1e18) #define PI (acos(-1)) #define EPS (1e-7) #define DEPS (1e-10) const ll mod = (ll)(INF); int main(){ int n; cin >> n; v(int) a(n); rep(i, n) cin >> a[i]; int r = (int)(sqrt((double)n)+0.5 + EPS); v(ll) dp(n); v(v(ll)) sum(r+1, v(ll)(r)); dp[0] = 1; rep(i, n) { rep2(j, 1, r) dp[i] = (dp[i] + sum[j][(i+1)%j]) % mod; if (i+11) dp[i+1] = (dp[i+1] + dp[i]) % mod; if (a[i]<=r) sum[a[i]][(i+1)%a[i]] = (sum[a[i]][(i+1)%a[i]] + dp[i]) % mod; else for (ll i2=i+a[i]; i2<=n-1; i2+=a[i]) dp[i2] = (dp[i2] + dp[i]) % mod; } cout << dp[n-1] << endl; return 0; }