#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define bn binary_search
#define sz(x) int((x).size())
#define lz(x) long long((x).size())
#define INF 1000000007
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ll> vl;
typedef pair<ll,ll> il;
typedef vector<ii> vii;
typedef vector<il> vil;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<string> vs;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<pair<int,ii>> gw;
typedef vector<pair<ll,il>> lw;
typedef vector<vc> vvc;
void solve(){
ll n;
cin>>n;
vl in(n);
bool ban1=true,ban2=true;
for(ll i=0;i<n;i++){
cin>>in[i];
if(i>0){
if(in[i]<in[i-1]) ban1=false;
}
if(in[i]>1) ban2=false;
}
if(ban1){
cout<<0<<endl;
return;
}
if(ban2){
vl a(n,0);
for(ll i=1;i<n-1;i++){
if(!in[i-1]){
a[i]=a[i-1]+1;
}else a[i]=a[i-1];
}
vl b(n,0);
for(ll i=n-2;i>=1;i--){
if(!in[i+1]) b[i]=b[i+1]+1;
else b[i]=b[i+1];
}
/*for(ll i=0;i<n;i++){
cout<<a[i]<<" ";
}
cout<<endl;
for(ll i=0;i<n;i++){
cout<<b[i]<<" ";
}*/
ll ans=0;
for(ll i=0;i<n;i++){
if(in[i]){
ans+=a[i]*b[i];
}
}
cout<<ans<<endl;
return;
}
ll ans=0;
for(ll i=1;i<n-1;i++){
ll left=0,right=0;
for(ll j=0;j<n;j++){
if(j<i&&in[i]>in[j]){
left++;
}else if(j>i&&in[i]>in[j]) right++;
}
ans+=left*right;
}
cout<<ans<<endl;
}
int main(){
ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
solve();
return 0;
}
