#!/usr/bin/python3
# -*- coding: utf-8 -*-
 
class Infile:
	def __init__(self,infile):
		self.data = []
		self.f = open(infile,"rb")
		self.readAll()
	def getByte(self,position):
		return self.data[position]
	def readAll(self):
		self.data = self.f.read()
 
 
 
def filetype(infile):
	try:
		f = Infile(infile)
		types = [["image/png", [0x89,0x50,0x4E,0x47,0x0D,0x0A,0x1A]], ["image/jpg", [0xFF,0xD8,0xFF,0xE0]], ["image/jpg", [0xFF,0xD8,0xFF,0xE1]],
				 ["image/gif", [0x47,0x49,0x46,0x38]], ["application/pdf", [0x25,0x50,0x44,0x46]], ["application/zip", [0x50,0x4B,0x03,0x04]],
				 ["application/zip", [0x50,0x4B,0x4C,0x49,0x54,0x45]], ["application/zip", [0x50,0x4B,0x53,0x70,0x58]],
				 ["application/zip", [0x50,0x4B,0x05,0x06]], ["application/zip", [0x50,0x4B,0x07,0x08]],
				 ["application/zip", [0x57,0x69,0x6E,0x5A,0x69,0x70]], ["application/zip", [0x50,0x4B,0x03,0x04,0x14,0x00,0x01,0x00]],
				 ["text/html", [0x3C,0x21,0x64,0x6F,0x63,0x74,0x79,0x70]], ["text/xml", [0x3C,0x3F,0x78,0x6D,0x6C,0x20]]]
		temp_t = {}
		idx = 0
		while idx<len(types):
			temp_t[idx] = True
			idx += 1
		i = 0
		anybody = False
		while True:
			byte = f.getByte(i)
			idx = 0
			while idx<len(types):
				if temp_t[idx]:
					anybody = True
					if len(types[idx][1])<=i:
						return types[idx][0]
					if types[idx][1][i] != byte:
						temp_t[idx] = False
				idx += 1
			i+=1
			if not anybody:
				break
			anybody = False
		idx = 0
		while idx<len(f.data):
			byte = f.data[idx]
			if byte == 0x0:
				return "Error/Unknown"
			idx += 1
		return "text/plain" 
	except:
		return "error/IOError"
print(filetype("book.pdf"))