ll@N,@A[N],@Q,S[N+2]{},j,s;rep(i,N){s=0;if(A[j=i])while(j<N&&A[j])s+=A[j++];while(i<j)S[++i]=s;}rep(Q){ll@--X,@B;wt(A[X]?S[X+1]-A[X]+B:S[X]+B+S[X+2]);}