#include using namespace std; const long long mod = 998244353; int main() { int n; cin >> n; vector a(n); for (int i = 0; i < n; i++) { cin >> a[i]; } map mp; long long ans = 0; for (int i = 0; i < n; i++) { ans += mp[a[i] - 1]; ans %= mod; mp[a[i]] += mp[a[i] - 1] + 1; mp[a[i]] %= mod; } cout << ans << endl; return 0; }