#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e6+5;
ll a[N],c[N],s=0;
int n;
void U(int x,int y){
	while(x<=n)c[x]+=y,x+=x&-x;
}
ll Q(int x){
	ll r=0;
	while(x)r+=c[x],x-=x&-x;
	return r;
}
ll Get(){
	int cur=0;
	ll sum=0;
	for(int i=18;i>=0;i--){
		if(cur+(1<<i)<=n&&c[cur+(1<<i)]+sum<=s/2){
			cur+=(1<<i);
			sum+=c[cur];
		}
	}
	ll ans=s-2*sum;
	if(cur<n){
		ans=min(ans,2*Q(cur+1)-sum);
	}
	return ans;
}
int main(){
	scanf("%d",&n);
	for(int i=1;i<n;i++){
		scanf("%lld",&a[i]);
		U(i,a[i]);
		s+=a[i];
	}
	cout<<Get()<<'\n';
	int q;
	scanf("%d",&q);
	for(int i=1;i<=q;i++){
		int x,y;
		scanf("%d%d",&x,&y);
		U(x,y-a[x]),s+=y-a[x],a[x]=y;
		cout<<Get()<<'\n';
	}
}