include <bits/stdc++.h>

define ll long long

using namespace std;
ll m,n;
ll a[500005],s=0;
int main()
{
cin>>m>>n;
for(int i=1;i<=n;i++)
cin>>a[i];
for(ll i=1;i<=n;i++)
{
ll j,k;
for(j=i;j>0;j--)
if(a[j]<a[i])
break;
for(k=i;k<=n;k++)
if(a[k]<a[i])
break;
s=max(s,(k-j-1)*a[i]);
}
cout<<s;
return 0;
}