N=int(input())
P=list(map(int,input().split()))
Q=[0]*N
for i in range(N):
  Q[P[i]-1]=i
def Binit(B,siz):
  while len(B)<siz+1:
    B.append(0)
  while len(B)>siz+1:
    del B[-1]
  for i in range(siz+1):
    B[i]=0
  B.append(siz)

def Badd(B,a,x):
  z=a
  while z<=B[-1]:
    B[z]+=x
    z+=(z&(-z))

def Bsum(B,a):
  r=0
  z=a
  while z>0:
    r+=B[z]
    z-=(z&(-z))
  return r

BIT=[]
Binit(BIT,N+3)
ANS=0
for i in range(N):
  ANS+=i-Bsum(BIT,Q[i]+1)
  Badd(BIT,Q[i]+1,1)
print(ANS)