#include <bits/stdc++.h>
using namespace std;
const int N = 500010;
typedef long long LL;
LL ans;
int n;

// 似乎结构体对于线段树不友好，不准备采用
struct Node {
    int val;
    int id;
} b[N];

bool cmp(Node a, Node b) {
    if (a.val == b.val) return a.id < b.id; // 值相等时，号小的在前
    return a.val < b.val;                   // 值小的在前
}

int tr[N];

int lowbit(int x) {
    return x & -x;
}

void add(int x, int c) {
    for (int i = x; i <= n; i += lowbit(i)) tr[i] += c;
}

int sum(int x) {
    int res = 0;
    for (int i = x; i; i -= lowbit(i)) res += tr[i];
    return res;
}

int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> b[i].val;
        b[i].id = i;
    }
    sort(b + 1, b + 1 + n, cmp);

    for (int i = 1; i <= n; i++) {
        add(b[i].id, 1);
        ans += sum(n) - sum(b[i].id); // 因为是值小的提前进场，如果值一样，则号小的先进场，那么发现有值比我小，号比我大的，就是逆序了
    }
    printf("%lld\n", ans);
    return 0;
}