#!/usr/bin/env zsh

local -i COLUMNS=1024
local -i x y=${#1} m
if (( y )); then
  while (( ${${(%):-$1%$y(l.1.0)}[-1]} )); do
    x=y
    (( y *= 2 ))
  done
  while (( y > x + 1 )); do
    (( m = x + (y - x) / 2 ))
    (( ${${(%):-$1%$m(l.x.y)}[-1]} = m ))
  done
fi
typeset -g REPLY=$x