Bash Chocolates By Numbers
gcd() {
    local _n=$1 _m=$2
    if (( _n % _m == 0 )); then
        echo "$_m"
        return
    fi
    gcd "$_m" $(( _n % _m ))
}

chocolates_by_numbers() {
    local _n=$1 _m=$2
    local _g
    _g=$(gcd "$_n" "$_m")
    echo $(( (_n * _m / _g) / _m ))
}

This uses the greatest common divisor to figure out how many chocolates get eaten before the pattern repeats.