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//gcc 5.4.0

#include  <bits/stdc++.h>
#include "teatr.h"
#include "message.h"
using namespace std;
int t[1000111], temp[1000111];
long long res = 0;


void mergeSort(int l, int r) {
    if(l == r) return;
    int mid = (l+r)/2;
    mergeSort(l, mid);
    mergeSort(mid+1, r);
    int in1 = l, in2 = mid+1, in3 = 0;
     while ((in1 <= mid) && (in2 <= r)) { 
        if (t[in1] <= t[in2]) { 
            in3++;
            temp[in3] = t[in1];
            in1++;
        } 
        else { 
            in3++;
            temp[in3] = t[in2];
            in2++;
            res += (mid - in1+1); 
        } 
    }
    
    
    while (in1 <= mid){
        in3++;
        temp[in3] = t[in1]; 
        in1++;
    }
    while (in2 <= r){
        in3++;
        temp[in3] = t[in2]; 
        in2++;
    }
    
    int pom = 0; 
    for (int i = l; i <= r; i++) { 
        pom++;
        t[i] = temp[pom];
    }
}

int main(void)
{
    if(MyNodeId() != 0) return 0;
    int n = GetN();
    for(int i = 0; i < n; i++) {
        t[i] = GetElement(i);
    }
    mergeSort(0, n-1);
    printf("%lld\n", res);
}