n=int(input())
a=list(map(int,input().split()))
r=list(range(n))
v=a[:]

def union(x,y):
  rx=root(x)
  ry=root(y)
  if rx==ry:
    return
  if rx>ry:
    rx,ry=ry,rx
  r[ry]=rx
  v[rx]+=v[ry]
  v[ry]=0
  return

def root(x):
  p=x
  l=[p]
  while r[p]!=p:
    p=r[p]
    l+=[p]
  for p in l:
    r[p]=l[-1]
  return r[x]

for i in range(n-1):
  if a[i]!=0 and a[i+1]!=0:
    union(i,i+1)

Q=int(input())
for _ in range(Q):
  x,b=map(int,input().split())
  x-=1
  rx=root(x)
  if a[x]==0:
    g=b
    if x+1<n and a[x+1]!=0:
      g+=v[root(x+1)]
    if x-1>=0 and a[x-1]!=0:
      g+=v[root(x-1)]
    print(g)
  else:
    print(v[rx]-a[x]+b)