HTMLify

func hg_sum(x int, y int, mat [][]int) int {
    var sum int
    sum += (mat[y-1][x-1] + mat[y-1][x] + mat[y+1][x-1])
    sum += mat[y][x]
    sum += (mat[y-1][x+1] + mat[y+1][x] + mat[y+1][x+1])
    return sum
}
func maxSum(grid [][]int) int {
    var max int
    for i:=1; i<len(grid)-1; i++ {
        for j:=1; j<len(grid[0])-1; j++ {
            sum := hg_sum(j, i, grid)
            if sum > max {
                max = sum
            }
        }
    }
    return max
}