#include<stdio.h>
#include<limits.h>

int compTimes = 0;

void merge(int A[], int left, int mid, int right){
	int n1 = mid - left;
	int n2 = right - mid;
	int L[n1+1], R[n2+1];
	int i, j, k;
	for( i = 0; i < n1; i++ ){ L[i] = A[left+i]; }
	for( i = 0; i < n2; i++ ){ R[i] = A[mid+i]; }
	L[n1] = INT_MAX;
	R[n2] = INT_MAX;
	i = 0;
	j = 0;
	int c = 0;
	for( k = left; k < right; k++ ){
		if( L[i] <= R[j] ){
			A[k] = L[i++];
			c++;
		}else{
			if( c < n1 ){ compTimes += n1 - c; }
			A[k] = R[j++];
		}
	}
	return;
}

void mergeSort(int A[], int left, int right){
	if( left+1 <  right ){
		int mid = (left + right) / 2;
		mergeSort(A, left, mid);
		mergeSort(A, mid, right);
		merge(A, left, mid, right);
	}
	return;
}

int main(){
	int A[200000], S[200000];
	int n, i, j, count = 0;
	scanf("%d", &n);
	for( i = 0; i < n; i++ ){
		scanf("%d", &A[i]);
		S[i] = A[i];
	}
	mergeSort(S, 0, n);
	printf("%d\n", compTimes);
	return 0;
}