#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
#define M 35000
#define N 50050
#define ll long long
#define lowbit(x) (x&-x)
int tree[M];
int num[N];
ll tmp[N];
int sum(int rt)
{
    int s=0;
    while(rt>0){
        s+=tree[rt];
        rt-=lowbit(rt);
    }
    return s;
}
void update(int rt)
{
    while(rt<=M-1){
        tree[rt]++;
        rt+=lowbit(rt);
    }
}
int main()
{
    int n;
    while(~scanf("%d",&n)){
        memset(tree,0,sizeof(tree));
        for(int i=1;i<=n;i++){
            scanf("%d",&num[i]);
            num[i]++;
        }
        ll ans=0;
        for(int i=1;i<=n;i++){
            tmp[i]= sum(num[i]-1);
            update(num[i]);
        }
        memset(tree,0,sizeof(tree));
        for(int i=n;i>=1;i--)
        {
            ans+=tmp[i]*(ll)sum(num[i]-1);
            update(num[i]);
        }
        printf("%lld\n",ans);
    }
    return 0;
}