Problem

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Bowling alley

Problem

Do you want to become a Jedi? Then we give you the code of peacekeeping knights:
No excitement — there is peace
No ignorance — have knowledge
No passion — there is serenity
No chaos — there is harmony
No death — there is Power

In addition to constant training, Padawans still have time for rest and some entertainment. One of my favorites is bowling alley.

N pins are placed in one row, numbered from left to right with numbers from 1 to N. Then, K balls are thrown along this row, while the ith ball knocks down all pins with numbers from li up to ri inclusive.
Your task is to determine which skittles are left standing.

Input 
The program receives as input the number of pins N and the number of throws K. Next comes K pairs of numbers liri, while \(1<=l_i<=r_i<=N\).

Imprint 
The program should output a sequence of N characters, where jth character is “I” if  j-th pin remained standing, or “.” if j-th pin was knocked down.
 
Example
# Input Output
1 10 3
8 10
25
36
I.....I...