#include<bits/stdc++.h>
using namespace std;
char a[300010]={0};
int main()
{
	freopen("Time.in","r",stdin);
	freopen("Time.out","w",stdout); 
	long long n,q,l,r,b,ans,i,j,k,m;
	cin>>n>>q;
	for(i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	for(i=1;i<=q;i++)
	{
		cin>>l>>r;
		ans=0;
		for(j=l;j<=r-2;j++)
		{
			for(k=r;k<=j+2;k--)
			{
				for(m=j+1;m<=k-1;m++)
				{
					cout<<"::debug 1"<<endl;
					if(a[m]==a[k]&&a[m]!=a[j]&&ans<(m-j)*(k-m))
					{
						ans=(m-j)*(k-m);
					}
				}
			}
		}
		cout<<ans;
	}
    return 0;
}