Nenokku (Easy)
A renowned author, famous for his bestselling book, has embarked on writing a sequel. He composes all his works on a computer connected to the Internet. Due to this oversight, a boy named Nenokku managed to access the unfinished manuscript. Each evening, Nenokku sneaks into the writer's computer to copy the latest additions onto his own device. After transferring a new chapter, Nenokku becomes curious about whether the author has used the word "book." However, since he prefers browsing the Internet over reading, he asks you to determine if certain words appear in the text. Naturally, he is interested in more than just one word.
Input
The input file consists of lines containing one of two types of entries:
? <word> (<word> is a sequence of up to 50 Latin characters);
A <text> (<text> is a sequence of up to 10^5 Latin characters).
1 indicates a request to check if the substring <word> is present in the text.
2 indicates the addition of <text> to the text.
The author has just begun working on the piece, so he couldn't have written more than 50 characters. The input file contains no more than 1 kilobyte of data.
Output
For each line of type 1, output "YES" if the substring <word> is found, and "NO" otherwise. The search should be case-insensitive.