#include
     
      void Merge(int ,int ,int );void mergeSort(int ,int );int ch[20000],temp[20000];int count = 0;void mergeSort(int lo,int hi) {    if(lo < hi)     {        int mid =( lo + hi ) / 2;        mergeSort(lo,mid);        mergeSort(mid + 1,hi);        Merge(lo,mid,hi);    }}void Merge(int lo,int mid,int hi) {    int i = lo;    int j = mid + 1;    int x = lo;    while(i <= mid&&j <= hi)     {        if ( ch[i] > ch[j])         {            count+=  mid - i + 1;            temp[x++] = ch[j++];        }         else        {            temp[x++] = ch[i++];        }    }    while(i <= mid) temp[x++] = ch[i++];    while(j <= hi)  temp[x++] = ch[j++];    for(int k = lo; k <= hi ; k++)        ch[k]  = temp[k];}int main() {    int N;    scanf("%d",&N);    for(int i=0; i < N; i++)     {        scanf("%d",&ch[i]);    }    mergeSort(0,N-1);    printf("%d\n",count);    return 0;}