#include <bits/stdc++.h>
#define INF 1000000000
#define ll long long
#define MAX_N 30
using namespace std;
struct SegmentTree{
ll s = 0;
SegmentTree * left = NULL, * right = NULL;
SegmentTree(int l,int r,vector<int> &a){
if(l == r){
s = (ll)a[l];
}else{
int mid = (l+r)/2;
left = new SegmentTree(l,mid,a);
right = new SegmentTree(mid+1,r,a);
s = left->s + right->s;
}
}
void upd(int l,int r,int p,int k){
if(l == p && r == p){
s += k;
//cout << l << ' ' << r << ' ' << s << endl;
}
else{
int mid = (l+r)/2;
if(p <= mid)
left->upd(l,mid,p,k);
else
right->upd(mid+1,r,p,k);
s = left->s + right->s;
}
}
ll rsq(int l,int r,int ss,int e){
if(l >= ss && r <= e)
return s;
else if(l > e || r < ss)
return 0;
else{
int mid = (l+r)/2;
return left->rsq(l,mid,ss,e) + right->rsq(mid+1,r,ss,e);
}
}
};
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
ll h[n];
set<ll> s;
map<ll,int> trlt;
for(int i = 0; i < n; i++){
cin >> h[i];
s.insert(h[i]);
}
int c = 0;
for(auto x : s){
trlt[x] = c++;
}
for(int i = 0; i < n; i++){
h[i] = trlt[h[i]];
}
vector<int> a(MAX_N+1,0);
SegmentTree st_left(0,MAX_N,a);
for(int i = 0; i < n; i++){
a[h[i]]++;
}
SegmentTree st_right(0,MAX_N,a);
st_left.upd(0,MAX_N,h[0],1);
st_right.upd(0,MAX_N,h[0],-1);
st_right.upd(0,MAX_N,h[1],-1);
ll ans = 0;
for(int i = 1; i < n-1; i++){
if(h[i] > 0) ans += st_left.rsq(0,MAX_N,0,h[i]-1) * st_right.rsq(0,MAX_N,0,h[i]-1);
st_left.upd(0,MAX_N,h[i],1);
st_right.upd(0,MAX_N,h[i+1],-1);
}
cout << ans << endl;
return 0;
}
