COCI '19 Contest 3 #2 Grudanje
View as PDFPatrik loves to study words in the English language. He especially loves words that contain exactly  letters. When he sees such a word, he instantly starts observing 
 of its subwords and for each of those subwords he determines whether all of its letters are distinct. If that is the case for each of the 
 subwords, then he considers the original word to be perfect.
Krešimir doesn't love studying English words, he loves to throw snowballs at Patrik instead. On a cold, winter morning, he was walking around town carrying exactly  snowballs and stumbled upon Patrik who was observing a giant 
-lettered word that was written on the wall by some hooligans. What a coincidence…
Krešimir fiercely threw the first snowball in Patrik's direction, but Patrik skillfully dodged the snowball so it hit and completely covered the -st letter of the word on a wall. In a similar manner, Krešimir failed to hit Patrik with the next 
 snowballs. More precisely, his 
-th snowball missed Patrik and completely covered the 
-th letter of the word on a wall. Interestingly enough, after Krešimir threw all of the snowballs, the entire word was covered in snow.
Patrik glanced at the completely covered word and concluded that it was perfect. Therefore, he needed to slightly alter his definition of a perfect word. The word is perfect if none of the  subwords contain two equal letters that are not covered in snow. Now he wants to know after which snowball (possibly zero) did the word on the wall become perfect.
Input
The first line contains a word that consists of  
 lowercase letters from the English alphabet.
The second line contains an integer  
 from the task description.
The -th of the next 
 lines contains two integers 
 and 
 
 which denote that the 
-th of the 
 subwords from the task description spans from 
-th to the 
-th letter of the word on a wall.
The next line contains  different integers 
 
 from the task description.
Output
In the only line you should output after which snowball (possibly zero) did the word on the wall become perfect.
Scoring
In test cases worth a total of  points, it will hold 
.
In test cases worth additional  points, it will hold 
.
In test cases worth additional  points, the word will only contain letters 
a.
Sample Input 1
aaaaa
2
1 2
4 5
2 4 1 5 3
Sample Output 1
2
Sample Input 2
abbabaab
3
1 3
4 7
3 5
6 3 5 1 4 2 7 8
Sample Output 2
5
Explanation for Sample Output 2
The state of the word on the wall after each thrown snowball is:
abbab*ab
ab*ab*ab
ab*a**ab
*b*a**ab
*b****ab
******ab
*******b
********
Sample Input 3
abcd
1
1 4
1 2 3 4
Sample Output 3
0
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