#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define all(x) (x).begin(), (x).end()
using ll = long long;
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n;cin>>n;
  vector<ll> A(n);
  rep(i,n)cin>>A[i];
  ll q;cin>>q;
  dsu uf(n);
  rep(i,n-1){
    if(A[i]>0 && A[i+1]>0) uf.merge(i,i+1);
  }
  map<ll,ll> mp;
  ll cnt=0;
  rep(i,n){
    if(A[i]>0) cnt+=A[i];
    else{
      if(i>0){
        mp[uf.leader(i-1)]=cnt;
        cnt=0;
      }
    }
  }
  if(A[n-1]>0) mp[uf.leader(n-1)]=cnt;
  while(q--){
    ll x,b;cin>>x>>b;
    x--;
    if(A[x]>0){
      ll ans=mp[uf.leader(x)];
      cout<<ans-A[x]+b<<endl;
    }else{
      ll ans=b;
      if(x>0&&A[x-1]>0){
        ans+=mp[uf.leader(x-1)];
      }
      if(x<n-1&&A[x+1]>0){
        ans+=mp[uf.leader(x+1)];
      }
      cout<<ans<<endl;
    }
  }
}