#!/bin/bash
sum=0
if [ -n "$1" ]; then
    num=$1
    for ((i = 1; i <= num; i++)); do
        if [ $((i % 3)) -eq 0 ]; then
            sum=$((sum + i))
        fi
    done
    echo "The sum of numbers divisible by 3 from 1 to $num is: $sum"
else
    echo "Please provide a number as an argument."
fi