#include <cstdio>

using namespace std;
int i,j,m,n,x,y,a[100001],Max,Min,k,s[100001];
int main()
{
    freopen("sequencequery.in","r",stdin);
    freopen("sequencequery.out","w",stdout);
    scanf("%d %d\n",&n,&m);
    for(i=1; i<=n; i++)
    {
        scanf("%d",&a[i]);
        s[i]=s[i-1]+a[i];
    }
    for(i=1; i<=m; i++)
    {
        Min=0;Max=-9999999;
        scanf("%d %d\n",&x,&y);
        for(j=x; j<=y; j++)
        {
            k=s[x-1];
            if(s[j]-k-Min>Max) Max=s[j]-k-Min;
            if(s[j]-k<Min) Min=s[j]-k;
        }
        printf("%d\n",Max);
    }
    return 0;
}