#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, srt, end) for (long long i = (srt); i < (long long)(end); i++)
// Ref: https://qiita.com/ysuzuki19/items/d89057d65284ba1a16ac
#define dump(var)  do{std::cerr << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cerr << e << "\n";}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cerr << e << " "; } std::cerr << "\n";}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ std::cerr << "\n"; for(const auto& v : vv){ view(v); } }
template<typename T> void dump_cout(const T& v) { for(long long i = 0; i < v.size(); i++) std::cout << v[i] << (i == v.size()-1 ? "\n" : " "); }

void solve() {
    ll n;
    cin >> n;
    vector<ll> p(n);
    rep(i, 0, n) cin >> p[i];
    set<ll> st;
    rep(i, 0, n) st.insert(i+1);
    ll ans = 0;
    for(ll i = n-1; i >= 0; i--) {
        auto itr = st.upper_bound(p[i]);
        if(itr == st.end()) {
            if(st.count(p[i])) {
                st.erase(p[i]);
            } else {
                ans -= i+1;
                st.erase(*st.begin());
            }
        } else {
            st.erase(*itr);
            ans += i+1;
        }
    }
    cout << ans << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}