codeflash-internal/experiments/pie_test_set/p02957.py

56 lines
996 B
Python

def problem_p02957(input_data):
import array
import bisect
import collections
import copy
import fractions
import heapq
import itertools
import math
import queue
import random
import re
import string
import sys
import time
sys.setrecursionlimit(10**7)
inf = 10**20
mod = 10**9 + 7
dd = [(-1, 0), (0, 1), (1, 0), (0, -1)]
ddn = [(-1, 0), (-1, 1), (0, 1), (1, 1), (1, 0), (1, -1), (0, -1), (-1, -1)]
def LI():
return [int(x) for x in sys.stdin.readline().split()]
def LI_():
return [int(x) - 1 for x in sys.stdin.readline().split()]
def I():
return int(sys.stdin.readline())
def LS():
return sys.stdin.readline().split()
def S():
return eval(input_data)
def main():
a, b = LI()
x = max(a, b) - min(a, b)
if x % 2 == 1:
return "IMPOSSIBLE"
return max(a, b) - x // 2
# main()
return main()