#!/bin/bash

read -p "26-long sequence?" input

declare -A results
steps=(3 5 7 9 11)

for step in "${steps[@]}"; do
    decimated=""
    length=${#input}
    index=0

    while [ ${#decimated} -lt 26 ]; do
        char="${input:index:1}"

        if [[ ! "$decimated" =~ "$char" ]]; then
            decimated+="$char"
        fi

        index=$((index + step))

        if [ $index -ge $length ]; then
            index=$((index - length))
        fi
    done

    results["$step"]="$decimated"
done

echo "Original string: $input"
for step in "${steps[@]}"; do
    formatted_decimated=$(echo "${results[$step]}")
    echo -e ":: $formatted_decimated | ($step)"
done