#!/usr/bin/python3 
#
# 
import sys

def count_inversions_trivial(A):
    x = 0
    for i in range(1,len(A)):
        for j in range(i):
            if A[j] > A[i]:
                x += 1
    return x

def count_inversions(A):
    if len(A) < 2:
        return 0
    
    m = len(A)//2
    Aleft = A[:m]               # O(n)
    Aright = A[m:]              # O(n)
    count = count_inversions(Aleft) + count_inversions(Aright)
    i = 0
    j = 0
    k = 0
    while i < len(Aleft) or j < len(Aright):
        if i >= len(Aleft) or (j < len(Aright) and Aright[j] < Aleft[i]):
            A[k] = Aright[j]
            j += 1
            k += 1
            count += len(Aleft)-i
        else:
            A[k] = Aleft[i]
            i += 1
            k += 1

    return count

A = []
for l in sys.stdin:
    for n in l.split():
        A.append(int(n))

print(count_inversions(A))