I,R=input,range
J=lambda:map(int,I().split())
N,*_=J()
A=list(J())
S=[0]*(N+2)
i=j=s=0
while i<N:
	if A[i]:
		while j<N and A[j]:s+=A[j];j+=1
		for k in R(i,j):S[k+1]=s
	else:j=i+1;s=0
	i=j
for _ in R(int(I())):X,B=J();print(S[X]-A[X-1]+B if A[X-1]else S[X-1]+B+S[X+1])