#include <cstdio>

using namespace std;
int n,m,v[100010],s[100010],i,j,x,y,mn,mx,nr;
int main()
{
    freopen("sequencequery.in","r",stdin);
    freopen("sequencequery.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1; i<=n; i++)
    {
        scanf("%d",&v[i]);
        s[i]=s[i-1]+v[i];
    }
    for(i=1; i<=m; i++)
    {
        mx=-9999999;
        scanf("%d%d",&x,&y);
        for(j=x; j<=y; j++)
        {
            nr=s[x-1];
            if(s[j]-nr-mn>mx) mx=s[j]-nr-mn;
            if(s[j]-nr<mn) mn=s[j]-nr;
        }
        printf("%d\n",mx);
    }
    return 0;
}