Dispatch Log Callsign Lookup

A regional dispatch centre keeps its radio traffic as a single line of lowercase words separated by single spaces (a "transcript"). A supervisor wants to jump straight to the first word in the transcript that begins with a given callsign prefix. Given the transcript and the prefix, report the 1-indexed position of the first word whose leading letters exactly match the prefix. If no word qualifies, report -1.

Input format

• Line 1: the transcript, a string of lowercase English letters with words separated by exactly one space (no leading or trailing spaces, no two consecutive spaces).
• Line 2: the callsign prefix, a non-empty string of lowercase English letters.

Output format

Print a single integer: the 1-indexed position of the first word in the transcript that has the prefix as its prefix, or -1 if no word qualifies.

Constraints

• 1 <= length of the transcript <= 100
• 1 <= length of the prefix <= 10
• The transcript consists only of lowercase English letters and single spaces separating words.
• The prefix consists only of lowercase English letters.

i love eating burger
burg

4

this problem is an easy problem
pro

2