#include<bits/stdc++.h>

using namespace std;

const int N=;

int n,sum[N],x,m,a[N],pos[N],len[N],s[N],f[N];

int cmp(int x,int y)

{

    return pos[x]<pos[y];

}

int main()

{

    scanf("%d",&n);

    for (int i=;i<=n;i++)scanf("%d",&x),sum[i]=sum[i-]+x;

    scanf("%d",&m);

    for (int i=;i<=m;i++)

     {

         scanf("%d%d",&pos[i],&len[i]);

         f[i]=i;

     }

    sort(f+,f+m+,cmp);

    f[m+]=m+;

    pos[f[m+]]=n+;

    for (int i=;i<=m;i++)

     for (int j=pos[f[i]];j-pos[f[i]]+<=len[f[i]]&&j<pos[f[i+]];j++)

      if (j-len[f[i]]+>pos[f[i-]])a[j]=f[i];

    for (int i=;i<=n;i++)

     {

         s[i]=s[i-];

         if (a[i])s[i]=max(s[i],s[i-len[a[i]]]+sum[i]-sum[i-len[a[i]]]);

     }

    printf("%d",s[n]);

}