two dimensional slice in Go

rows_cols.go

package main

import (
    "fmt"
    "os"
    "strconv"
)


func main() {
    var a []string
    a= make([]string,21)
    a[0] = "zero"
    a[1] = "one"
    a[2] = "two"
    a[3] = "three"
    a[4] = "four"
    a[5] = "five"
    a[6] = "six"
    a[7] = "seven"
    a[8] = "eight"
    a[9] = "nine"
    a[10] = "ten"
/*
    a[11] = "eleven"
    a[12] = "twelve"
    a[13] = "thirteen"
    a[14] = "fourteen"
    a[15] = "fifteen"
    a[16] = "sixteen"
    a[17] = "seventeen"
    a[18] = "eightteen"
    a[19] = "nineteen"
    a[20] = "twenty"
*/
    // n=rows, m=cols
    n,_:= strconv.Atoi(os.Args[1])
    m,_:= strconv.Atoi(os.Args[2])

    frame := make([][]string, n)
    rows := make([]string, n*m)

    for i := 0; i < n; i++ {
        frame[i] =rows[i*m : (i+1)*m]
    }

    d := 0
    for i:= 0; i < n; i++ {
        if(d == len(a)) {
            break
        }
        //fmt.Println("i:", i)
        for j:= 0; j < m; j++ {
            //fmt.Println("i, j, d:", i, j, a[d])
            frame[i][j] = a[d]
            d += 1
            if(d == len(a)) {
                break
            }
        }
    }

    fmt.Println()
    fmt.Println()

    for i:= 0; i < n; i++ {
        fmt.Println(frame[i])
    }

    fmt.Println()
    fmt.Println("===================================================")
    fmt.Println()

    d = 0
    for j:= 0; j < m; j++ {
        if(d == len(a)) {
            break
        }
        //fmt.Println("j:", j)

        for i:= 0; i < n; i++ {
            //fmt.Println("i, j, d:", i, j, a[d])
            frame[i][j] = a[d]
            d += 1
            if(d == len(a)) {
                break
            }
        }
    }

    fmt.Println()
    fmt.Println()

    for i:= 0; i < n; i++ {
        fmt.Println(frame[i])
    }
}