Capitalise every word

You are given a line whose words are separated by single spaces. If the first character of a word is a lowercase Latin letter, replace it with the uppercase letter. The rest of the word and words that do not start with a letter stay the same.

A single line — a string of $1$ to $1000$ ASCII characters. Words are separated by single spaces; there are no spaces at the start or the end.

The changed string.

A word starts at the first character of the line or right after a space. aLREADY → ALREADY: only the first letter changes, there is no need to lowercase the rest. In the first example: Assalomu Alaykum Bo'lajak Dasturchilar!.