#!/usr/bin/env racket
#lang racket/base

(require racket/string)

(define line (list->vector (string->list (string-downcase (read-line)))))

(for ([i (vector-length line)])
  (let [(chance (>= 5 (random 10)))]
    (cond [chance (vector-set! line i (char-upcase (vector-ref line i)))])))

(displayln (list->string (vector->list line)))