// a is array and seg is segment_tree array (it is segment_tree_for max_range)
void build(int node,int i,int j)
{
    if(i==j)
    {
        seg[node]=a[i];
        return ;
    }

    int mid = (i+j)/2;

    build(2*node+1,i,mid);
    build(2*node+2,mid+1,j);

    seg[node]=max(seg[2*node+1],seg[2*node+2]);

}

ll query(int node,int i,int j,int l,int r)
{
    if(i>=l && j<=r)  //if this interval lies inside l--r
        return seg[node];

    if(i>r || j<l || r<l)return INT_MIN;

    int mid = (i+j)/2;
    return max( query(2*node+1,i,mid,l,r)   , query(2*node+2,mid+1,j,l,r) );
}