#ifdef ONLINE_JUDGE
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#endif
#include "bits/stdc++.h"
#define fast ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define fill(arr,val) memset(arr,val,sizeof(arr))
#define FOR(i, a, b) for(__typeof(b) i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for(__typeof(a) i = a, _b = b; i >= _b; --i)
#define ALL(a) (a).begin(), (a).end()
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define ll long long
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define ii pair<int,int>
#define iii pair<int,pair<int,int>>
#define dq deque<int>
#define nend '\n'
using namespace std;
const ll inf = 1e18;
const int dx[] = {1,0,-1,0};
const int dy[] = {0,1,0,-1};
const int MOD = 1e9 + 7;
const ll hashi = 2e9 + 11;
inline ll add(ll a, ll b) { return (a + b) % MOD; }
inline ll sub(ll a, ll b) { return ((a - b) % MOD + MOD) % MOD; }
inline ll mul(ll a, ll b) { return (a * b) % MOD; }
inline ll binpow(ll a, ll b) {
ll res = 1;
a %= MOD;
while (b > 0) {
if (b & 1) res = res * a % MOD;
a = a * a % MOD;
b >>= 1;
}
return res;
}
inline ll modInverse(ll n) {
return binpow(n, MOD - 2);
}
inline ll modDivide(ll a, ll b) {
return (a % MOD * modInverse(b)) % MOD;
}
ll extended_gcd(ll a, ll b, ll& x, ll& y) {
if (b == 0) {
x = 1; y = 0;
return a;
}
ll x1, y1;
ll d = extended_gcd(b, a % b, x1, y1);
x = y1;
y = x1 - y1 * (a / b);
return d;
}
void init_code() {
fast;
// #ifndef ONLINE_JUDGE
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
// #endif
}
/// sorting books: one swap of adjacent "wrong" books fixes exactly 1 inversion
/// -> answer = number of inversions = pairs i<j with a[i]>a[j]
/// count with bit: go left to right, for a[i] count how many ALREADY inserted
/// values are bigger = (inserted so far) - (inserted values <= a[i])
/// values up to 1e9 -> compress to 1..n first. O(n log n)
/// answer can be n*(n-1)/2 ~ 2e10 -> ll
const int N=2e5+5;
int n,a[N],bit[N];
void upd(int i) {
for (; i<=n; i+=i&-i) bit[i]++;
}
int get(int i) {
int s=0;
for (; i>0; i-=i&-i) s+=bit[i];
return s;
}
void solve() {
cin >> n;
FOR(i,1,n) cin >> a[i];
vector<int> v(a+1,a+n+1);
sort(ALL(v));
v.erase(unique(ALL(v)),v.end());
FOR(i,1,n) a[i]=lower_bound(ALL(v),a[i])-v.begin()+1;
ll res=0;
FOR(i,1,n) {
res+=(i-1)-get(a[i]); ///inserted before, but bigger than a[i]
upd(a[i]);
}
cout << res << nend;
}
int main() {
init_code();
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
