package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"strings"
	"unicode"
)

// Function to encode characters into their respective number pairs
func encodeChar(char rune) int {
	// Define the alphabet and numbers with a leading space
	alphabet := " ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

	// Find the index of the character
	index := strings.IndexRune(alphabet, char)
	if index == -1 {
		return -1 // Return -1 if character is not found
	}
	return index
}

// Function to apply shift and wrap around
func applyShift(value, shift int) int {
	shifted := (value + shift) % 37
	if shifted < 0 {
		shifted += 37
	}
	return shifted
}

// Function to format the output based on group size and line size
func formatOutput(encoded []int, groupSize int, lineSize int) string {
	var output strings.Builder
	for _, num := range encoded {
		output.WriteString(fmt.Sprintf("%02d", num))
	}

	// Apply grouping
	finalOutput := output.String()
	var groupedOutput strings.Builder
	counter := 0
	groupCounter := 0

	for i := 0; i < len(finalOutput); i += groupSize {
		if i+groupSize < len(finalOutput) {
			groupedOutput.WriteString(finalOutput[i:i+groupSize] + " ")
		} else {
			groupedOutput.WriteString(finalOutput[i:])
		}
		counter++
		groupCounter++

		// Check if we reached the line size
		if lineSize > 0 && groupCounter >= lineSize && i+groupSize < len(finalOutput) {
			groupedOutput.WriteString("\n")
			groupCounter = 0
		}
	}

	return strings.TrimSpace(groupedOutput.String())
}

func main() {
	// Define command-line flags
	shift := flag.Int("s", 0, "Shift amount for the cipher")
	groupSize := flag.Int("g", 0, "Group size for output formatting")
	lineSize := flag.Int("l", 0, "Line size by number of groups")
	flag.Parse()

	// Read input from stdin
	reader := bufio.NewReader(os.Stdin)
	input, _ := reader.ReadString('\n')
	input = strings.TrimSpace(input)

	var encoded []int

	// Encode the input string
	for _, char := range input {
		if !unicode.IsLetter(char) && !unicode.IsDigit(char) && char != ' ' {
			continue // Skip characters not in the defined alphabet and numbers
		}
		encodedValue := encodeChar(unicode.ToUpper(char))
		if encodedValue == -1 {
			continue // Skip characters not found in the alphabet string
		}
		shiftedValue := applyShift(encodedValue, *shift)
		encoded = append(encoded, shiftedValue)
	}

	// Format the output
	formattedOutput := formatOutput(encoded, *groupSize, *lineSize)
	fmt.Println(formattedOutput)
}