Problem:


Score : 200 points

Problem Statement

We have a board with H horizontal rows and W vertical columns of squares.
There is a bishop at the top-left square on this board.
How many squares can this bishop reach by zero or more movements?

Here the bishop can only move diagonally.
More formally, the bishop can move from the square at the r_1-th row (from the top) and the c_1-th column (from the left) to the square at the r_2-th row and the c_2-th column if and only if exactly one of the following holds:

r_1 + c_1 = r_2 + c_2

r_1 - c_1 = r_2 - c_2

For example, in the following figure, the bishop can move to any of the red squares in one move:

Constraints

1 \leq H, W \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

H \ W

Output

Print the number of squares the bishop can reach.

Sample Input 1

4 5

Sample Output 1

10

The bishop can reach the cyan squares in the following figure:

Sample Input 2

7 3

Sample Output 2

11

The bishop can reach the cyan squares in the following figure:

Sample Input 3

1000000000 1000000000

Sample Output 3

500000000000000000



Sample input:
4 5


Sample output:
10

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
import sys
import math

def solve(H: int, W: int):
    if H==1 or W == 1:
        print(1)
    else:
        evenRow = math.ceil(W/2)
        oddRow = math.floor(W/2)
        r = H//2
        extra= evenRow if H %2==1 else 0
        print(r*evenRow+r*oddRow+extra)
    return


# Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    H = int(next(tokens))  # type: int
    W = int(next(tokens))  # type: int
    solve(H, W)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
h, w = map(int, input().split())

if(h == 1 or w == 1):
    print(1)
else:
    if(h*w % 2 == 0):
        print(h*w // 2)
    else:
        print(h*w//2 + 1)

Submission status: Accepted

Solution code:
import math

H, W = map(int, input().split())

if H == 1 or W == 1:
    print(1)
else:
    h1 = math.ceil(H / 2)
    w1 = math.ceil(W / 2)
    h2 = math.floor(H / 2)
    w2 = math.floor(W / 2)

    print(h1*w1 + h2*w2)

Submission status: Accepted

Solution code:
h, w = [int(i) for i in input().split()]
if h == 1 or w == 1:
    print(1)
    exit()
    
a = (h + 1) // 2
b = h // 2
c = (w + 1) // 2
d = w // 2
print(a*c+b*d)

Submission status: Accepted

Solution code:
H,W=map(int,input().split())
if H==1 or W==1:
    print(1)
else:
    if (H*W)%2==1:
        print((H*W+1)//2)
    else:
        print((H*W)//2)

Submission status: Accepted

Solution code:
h, w = map(int, input().split())
if h == 1 or w == 1:
  print(1)
elif (h * w) % 2 == 1:
  print((h * w + 1) // 2)
else:
  print((h * w) // 2)

Submission status: Accepted

Solution code:
H, W = map(int, input().split())
if H == 1 or W == 1:
    print(1)
    exit()

if H*W % 2 != 0:
    print(H*W//2+1)
else:
    print(H*W//2)

Submission status: Accepted

Solution code:
h, w = map(int, input().split())

num = h * w

if h == 1 or w == 1:
    print(1)
elif num % 2 == 0:
    print(num // 2)
else:
    print(num // 2 + 1)

Submission status: Accepted

Solution code:
from sys import exit, setrecursionlimit
setrecursionlimit(10**6)

def array2D(row, col ,val=0):
    return [[val]*col for i in range(row)]

from math import ceil
h,w = map(int, input().split())
ans = 0

if h==1 or w == 1:
    print(1)
else:
    print((h-h//2)*(w-w//2) + (h//2) * (w//2))

Submission status: Accepted

Solution code:
h, w = map(int, input().split())
hw = h * w

if h == 1 or w == 1:
    print(1)
elif hw % 2 == 0:
    print(h * w // 2)
else:
    print(h*w // 2 + 1)

Submission status: Accepted

Solution code:
n,m = (int(x) for x in input().split())

mul = int(n*m)

if n == 1 or m == 1:
    print(1)
elif mul % 2 == 1:
    print(mul // 2 + 1)
elif mul % 2 == 0:
    print(mul //2)

Submission status: Accepted

Solution code:
import math
h, w = list(map(int, input().split(" ")))

if h == 1 or w == 1:
    print(1)
    exit()

print(math.ceil((h * w) / 2))

Submission status: Accepted

Solution code:
N,K=map(int,input().split())

if N==1 or K==1:
  print(1)
else:
  if N%2==0:
    print((N//2)*K)
  else:
    if K%2==0:
      print((K//2)*N)
    else:
      print(N*(K//2)+(N//2)+1)

Submission status: Accepted

Solution code:
def main():
    h, w = list(map(int, input().split()))
    if (h==1 or w==1):
        print(1)
    elif (h%2==0 or w%2==0):
        print(int((h*w)/2))
    else:
        print(int((h*w)//2+1))

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
[H,W]=[int(inp) for inp in input().split()]
if H == 1 or W == 1:
    print(1)
    exit()
yokoKisu = H // 2 + H % 2

sum=H*(W//2)+yokoKisu*(W%2)
print(sum)

Submission status: Accepted

Solution code:
H,W = map(int, input().split())
if H*W%2 == 0:
    ans = H*W//2
else:
    ans = H*(W-1)//2 + (H+1)//2
if H == 1 or W == 1:
    ans = 1
print(ans)

Submission status: Accepted

Solution code:
import math
H, W = [int(_) for _ in input().split(" ")]
if (H == 1 or W == 1):
  print(1)
elif (H % 2 == 0):
  print(int(H/2*W))
else:
  print(int(H/2)*W+math.ceil(W/2))

Submission status: Accepted

Solution code:
h,w=input().strip().split(" ")
h,w=[int(h),int(w)]
p=h*w
if h==1 or w==1:
    print(1)
else:
    if p%2==1:
        print((p//2)+1)
    else:
        print(p//2)

Submission status: Accepted

Solution code:
H, W = map(int, input().split())

s = H * W

if H == 1 or W == 1:
    print(1)
else:
    if s % 2 == 0:
        print(s // 2)
    else:
        print(s // 2 + 1)

Submission status: Accepted

Solution code:
H,W = map(int, input().split())

if H == 1 or W == 1:
    ans = 1
else:
    ans = ((H + 2 - 1) // 2) * ((W + 2 - 1) // 2) + (H // 2) * (W//2)
print(ans)

Submission status: Accepted

Solution code:
h, w = map(int, input().split())
if h == 1 or w == 1:
  print(1)
elif h%2 == 0 and w%2 == 0:
  print(h*w//2)
elif h%2 == 1 and w%2 == 0:
  print((h-1)*w//2 + (w+1)//2)
elif h%2 == 0 and w%2 == 1:
  print(h*(w-1)//2 + (h+1)//2)
elif h%2 == 1 and w%2 == 1:
  print((h-1)*(w-1)//2+(h+1)//2+(w+1)//2-1)

Submission status: Accepted

Solution code:
H,W=map(int,input().split())
if H==1 or W==1:
  print(1)
  exit(0)
if W%2==0:
  w=W//2
  ans=w*H
else:
  w=W//2 + 1
  ans=w*H
  ans-=H//2
print(ans)

Submission status: Accepted

Solution code:
import math
def main():
    H,W=map(int, input().split())
    if H == 1 or W == 1:
        print(1)
    else:
        print((H//2)*W + (H%2)*math.ceil(W/2))
    return

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
h, w = [int(x) for x in input().split()]
if h == 1 or w == 1:
    print(1)
else:
    print((h * w + 1) // 2)

Submission status: Accepted

Solution code:
H, W = map(int, input().split())
def f(H, W):
    if H == 1 or W == 1:
        return 1
    if H % 2 == 0:
        return H // 2 * W
    else:
        return H // 2 * W + (W+1) // 2
print(f(H, W))

Submission status: Accepted

Solution code:
H, W = map(int, input().split())

if H == 1 or W == 1:
    print(1)
elif H%2==1 and W%2==1:
    print(int(H * W / 2) + 1)
else:
    print(int(H * W / 2))

Submission status: Accepted

Solution code:
def main(sample_file = ''):

    """ convenient functions
    # for i, a in enumerate(iterable)
    # q, mod = divmod(a, b)
    # divmod(x, y) returns the tuple (x//y, x%y)
    # Higher-order function: reduce(operator.mul, xyz_count, 1)
    # manage median(s) using two heapq https://atcoder.jp/contests/abc127/tasks/abc127_f
    """

    """convenient decorator
    # @functools.lru_cache():
    # to facilitate use of recursive function
        # ex:
        # from functools import lru_cache
        # import sys
        # sys.setrecursionlimit(10**9)
        # @lru_cache(maxsize=None)
        # def fib(n):
        #     if n < 2:
        #         return n
        #     return fib(n-1) + fib(n-2)
        # print(fib(1000))
    """
    
    # import numpy as np
    import sys
    sys.setrecursionlimit(10**7)
    from itertools import accumulate, combinations, permutations, product # https://docs.python.org/ja/3/library/itertools.html
    # accumulate() returns iterator! to get list: list(accumulate())
    from math import factorial, ceil, floor, sqrt
    def factorize(n):
        """return the factors of the Arg and count of each factor
        
        Args:
            n (long): number to be resolved into factors
        
        Returns:
            list of tuples: factorize(220) returns [(2, 2), (5, 1), (11, 1)]
        """
        fct = []  # prime factor
        b, e = 2, 0  # base, exponent
        while b * b <= n:
            while n % b == 0:
                n = n // b
                e = e + 1
            if e > 0:
                fct.append((b, e))
            b, e = b + 1, 0
        if n > 1:
            fct.append((n, 1))
        return fct
    def combinations_count(n, r):   
        """Return the number of selecting r pieces of items from n kinds of items.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        # TODO: How should I do when n - r is negative?
        if n < 0 or r < 0:
            raise Exception('combinations_count(n, r) not defined when n or r is negative')
        if n - r < r: r = n - r
        if r < 0: return 0
        if r == 0: return 1
        if r == 1: return n
        numerator = [n - r + k + 1 for k in range(r)]
        denominator = [k + 1 for k in range(r)]
        for p in range(2,r+1):
            pivot = denominator[p - 1]
            if pivot > 1:
                offset = (n - r) % p
                for k in range(p-1,r,p):
                    numerator[k - offset] /= pivot
                    denominator[k] /= pivot
        result = 1
        for k in range(r):
            if numerator[k] > 1:
                result *= int(numerator[k])
        return result
    def combinations_with_replacement_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items allowing individual elements to be repeated more than once.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        if n < 0 or r < 0:
            raise Exception('combinations_with_replacement_count(n, r) not defined when n or r is negative')
        elif n == 0:
            return 1
        else:
            return combinations_count(n + r - 1, r)
    from bisect import bisect_left, bisect_right
    from collections import deque, Counter, defaultdict # https://docs.python.org/ja/3/library/collections.html#collections.deque
    from heapq import heapify, heappop, heappush, heappushpop, heapreplace,nlargest,nsmallest # https://docs.python.org/ja/3/library/heapq.html
    from copy import deepcopy, copy # https://docs.python.org/ja/3/library/copy.html
    import operator
    from operator import itemgetter #sort 
    # ex1: List.sort(key=itemgetter(1))
    # ex2: sorted(tuples, key=itemgetter(1,2))
    from functools import reduce, lru_cache
    def chmin(x, y):
        """change minimum
        if x > y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current minimum value
            y (long): potential minimum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x > y:
            x = y
            return (x, True)
        else:
            return (x, False)
    def chmax(x, y):
        """change maximum
        if x < y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current maximum value
            y (long): potential maximum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x < y:
            x = y
            return (x, True)
        else:
            return (x, False)

    from fractions import gcd # Deprecated since version 3.5: Use math.gcd() instead.
    def gcds(numbers):
        return reduce(gcd, numbers)
    def lcm(x, y):
        return (x * y) // gcd(x, y)
    def lcms(numbers):
        return reduce(lcm, numbers, 1)
    def make_divisors(n, reversed=False):
        """create list of divisors
        
        Args:
            number (int): number from which list of divisors is created
            reversed (bool, optional): ascending order if False. Defaults to False.
        
        Returns:
            list: list of divisors
        """
        divisors = set()
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                divisors.add(i)
                divisors.add(n//i)
        return sorted(list(divisors),reverse=reversed)
    
    # first create factorial_list
    # fac_list = mod_factorial_list(n)
    INF = 10 ** 18
    MOD = 10 ** 9 + 7
    modpow = lambda a, n, p = MOD: pow(a, n, p) # Recursive function in python is slow!
    def modinv(a, p = MOD):
        # evaluate reciprocal using Fermat's little theorem:
        # a**(p-1) is identical to 1 (mod p) when a and p is coprime
        return modpow(a, p-2, p)
    def modinv_list(n, p = MOD):
        if n <= 1:
            return [0,1][:n+1]
        else:
            inv_t = [0,1]
            for i in range(2, n+1):
                inv_t += [inv_t[p % i] * (p - int(p / i)) % p]
            return inv_t
    def modfactorial_list(n, p = MOD):
        if n == 0:
            return [1]
        else:
            l = [0] * (n+1)
            tmp = 1
            for i in range(1, n+1):
                tmp = tmp * i % p
                l[i] = tmp
            return l
    def modcomb(n, k, fac_list = [], p = MOD):
        # fac_list = modfactorial_list(100)
        # print(modcomb(100, 5, modfactorial_list(100)))
        from math import factorial
        if n < 0 or k < 0 or n < k: return 0
        if n == 0 or k == 0: return 1
        if len(fac_list) <= n:
            a = factorial(n) % p
            b = factorial(k) % p
            c = factorial(n-k) % p
        else:
            a = fac_list[n]
            b = fac_list[k]
            c = fac_list[n-k]
        return (a * modpow(b, p-2, p) * modpow(c, p-2, p)) % p
    def modadd(a, b, p = MOD):
        return (a + b) % MOD
    def modsub(a, b, p = MOD):
        return (a - b) % p
    def modmul(a, b, p = MOD):
        return ((a % p) * (b % p)) % p
    def moddiv(a, b, p = MOD):
        return modmul(a, modpow(b, p-2, p))

    class UnionFindTree:
        """union find tree class
        TODO: fix this description...
        how to use (example):
        >>  uf = UnionFindTree(N) 
        >>  if uf.find_root(a) == uf.find_root(b):
        >>      do something
        >>  else:
        >>      do something
        >>      uf.unite(a, b)
        """
        def __init__(self, N):
            self.root = [-1] * (N+1)
            self.rank   = [0]  * (N+1)
            self.connected_num = [1] * (N+1)
    
        def find_root(self,x):
            root = self.root
            while root[x] != -1:
                x = root[x]
            return x
    
        def unite(self,x,y):
            root = self.root
            rank = self.rank
            connected_num = self.connected_num
            find_root = self.find_root
    
            rx = find_root(x)
            ry = find_root(y)
            if rx != ry:
                if rank[rx] < rank[ry]:
                    root[rx] = ry
                    rx,ry = ry,rx
                else:
                    if rank[rx] == rank[ry]:
                        rank[rx] += 1
                    root[ry] = rx       
                connected_num[rx] += connected_num[ry]

    # Graph: https://en.wikipedia.org/wiki/Directed_graph
    # Bellman-Ford: O(|V||E|). Use this if there exists an edge with negative length in the graph
    # After N steps, the shortest path has converded if there doesn't exist an cycle of edges with negative
    # Watch out: d[N] == d[2*N] doesn't necessarily mean the graph doesn't have negative cycle
    # ref: https://www.youtube.com/watch?v=1Z6ofKN03_Y

    def BellmanFord(N, M, ABC, vertex_start, vertex_end, value_if_inf = -1, find_shortest = False):
        """to calculate furthest or shortest length between vertex_start and vertex_end using BellmanFord algorithm
        
        Args:
            N (int): number of vertices
            M (int): number of edges
            ABC (list): [(ai, bi, ci) for _ in range(N)] where i-th edge is directed from vertex ai to vertex bi and the length is ci 
            vertex_start (int): start vertex. usually use 0.
            vertex_end (int): end vertex. usually use N-1.
            value_if_inf (int or string as you like, optional): value you want when the furthest (or shortest) distance is infinite (or -infinite). Defaults to -1.
            find_shortest (bool, optional): choose False to find furthest path. Defaults to False.
        
        Returns:
            int or string: normally int (but can be str if you set value_if_inf to str)
            
        Example:
                N, M, P = R()
                ABC = [R() for _ in range(M)]
                ABC = [(a-1, b-1, c-P) for a, b, c in ABC]
                print(BellmanFord(N, M, ABC, 0, N-1, value_if_inf = 'inf'))

        """

        def make_reachable_list(N, M, ABC, vertex_start, vertex_end):
            reachable_to_direct = defaultdict(list)
            reachable_from_direct = defaultdict(list)
            reachable_from_start = [False] * N
            reachable_to_end = [False] * N
            reachable_from_start[vertex_start] = True
            reachable_to_end[vertex_end] = True
            reachable_from_both_sides = [False] * N
            dfs_from_start = []
            dfs_to_end = []
            for a, b, c in ABC:
                reachable_to_direct[a].append(b)
                reachable_from_direct[b].append(a)
                if a == vertex_start:
                    dfs_from_start.append(b)
                    reachable_from_start[b] = True
                if b == vertex_end:
                    dfs_to_end.append(a)
                    reachable_to_end[a] = True
            while dfs_from_start:
                v = dfs_from_start.pop()
                for i in reachable_to_direct[v]:
                    if not reachable_from_start[i]:
                        reachable_from_start[i] = True
                        dfs_from_start.append(i)
            while dfs_to_end:
                v = dfs_to_end.pop()
                for i in reachable_from_direct[v]:
                    if not reachable_to_end[i]:
                        reachable_to_end[i] = True
                        dfs_to_end.append(i)
            for i in range(N):
                reachable_from_both_sides[i] = reachable_from_start[i] and reachable_to_end[i]
            return reachable_from_both_sides
        
        reachable_from_both_sides = make_reachable_list(N, M, ABC, vertex_start, vertex_end)
        
        if find_shortest:
            dist = [INF for i in range(N)]
        else:
            dist = [-INF for i in range(N)]
        
        dist[vertex_start] = 0
        for i in range(N):
            updated = False
            for a, b, c in ABC:
                if not reachable_from_both_sides[a]:
                    continue
                elif find_shortest:
                    update_condition = dist[a] + c < dist[b]
                else:
                    update_condition = dist[a] + c > dist[b]
                if dist[a] != INF and update_condition:
                    dist[b] = dist[a] + c
                    updated = True
                    if i == N-1:
                        return value_if_inf
            if not updated:
                break
        return dist[vertex_end]

    """ initialize variables and set inputs
    # initialize variables
        # to initialize list, use [0] * n
        # to initialize two dimentional array:
            # ex) [[0] * N for _ in range(N)]
            # ex2) dp = [[0] * (N+1) for _ in range(W*2)]
    # set inputs
        # put inputs between specific values (almost as quickly)
        # ex) S = [-INF] + [int(r()) for _ in range(A)] + [INF]
        # open(0).read() is sometimes useful:
        # ex) n, m, *x = map(int, open(0).read().split())
        #     min(x[::2]) - max(x[1::2])
        # ex2) *x, = map(int, open(0).read().split())
        #     don't forget to add comma after *x if only one variable is used
    # preprocessing
        # transpose = [x for x in zip(*data)]
        # ex) [[1, 2, 3], [4, 5, 6], [7, 8, 9]] => [(1, 4, 7), (2, 5, 8), (3, 6, 9)]
        # flat = [flatten for inner in data for flatten in inner]
        # ex) [[1, 2, 3], [4, 5, 6], [7, 8, 9]] => [1, 2, 3, 4, 5, 6, 7, 8, 9]
    # calculate and output
        # output pattern
        # ex1) print(*l) => when l = [2, 5, 6], printed 2 5 6
    """

    # functions to read input
    r = lambda: sys.stdin.readline().strip()
    r_int = lambda: int(r())
    r_float = lambda: float(r())
    R = lambda: list(map(int, r().split()))
    R_str = lambda: r().split()
    R_map = lambda: map(int, r().split())
    R_float = lambda: list(map(float, r().split()))
    R_tuple = lambda: tuple(map(int, r().split()))

    """ how to treat input
    # single int: int(r())
    # single string: r()
    # single float: float(r())
    # line int: R()
    # line string: r().split()
    # line (str, int, int): [j if i == 0 else int(j) for i, j in enumerate(r().split())]
    # lines int: [R() for _ in range(n)]
    """

    # for test
    if sample_file:
        sys.stdin = open(sample_file)
        
    # ----------------------------------
    # main
    
    H, W = R()
    if H==1 or W == 1:
        print(1)
    elif H % 2 == 0 and W % 2 == 0:
        print(H*W//2)
    elif H % 2 != 0 and W % 2 != 0:
        print(H*W//2+1)
    else:
        print(H*W//2)
    
    # end of main
    # ----------------------------------

    """memo: how to use defaultdict of list
    # initialize
    Dic = defaultdict(list)
    # append / extend
    Dic[x].append(y)
    # three methods for loop: keys(), values(), items()
    for k, v in Dic.items():
    """
    
    """memo: how to solve binary problems
    # to make binary digits text
    >>> a = 5
    >>> bin_str_a = format(a, '#06b')
    >>> print(bin_str_a)
    0b0101 # first 2 strings (='0b') indicates it is binary
    """
    
    """memo: how to solve the problem
    creating simple test/answer
    greed
    simple dp
    graph
    """

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
def main():
    H, W = map(int, input().split())
    if H == 1 or W == 1:
        print(1)
    else:
        print(-(-H*W//2))


if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
n,m=map(int,input().split())
if n==1 or m==1:
  print(1)
  exit()
print(m//2*n+m%2*(n//2+n%2))

Submission status: Accepted

Solution code:
import sys
input = lambda: sys.stdin.readline().rstrip() 

def resolve():
    H, W = map(int, input().split())
    if H==1 or W==1:
        print('1')
    else:
        print((H*W+1)//2)

if __name__ == '__main__':
    resolve()

Submission status: Accepted

Solution code:
import sys
input = sys.stdin.readline

H, W = map(int, input().split())
if H == 1 or W == 1:
    ans = 1
elif H%2 == 1 and W%2 == 1:
    ans = H*(W//2) + (H+1)//2
else:
    ans = H*W//2
print(ans)

Submission status: Accepted

Solution code:
import math
list = input().split(" ")
H = int(list[0])
W = int(list[1])

if (W == 1) or (H == 1):
    print(1)
else:
    print(math.ceil(H*W/2))

Submission status: Accepted

Solution code:
h, w = map(int, input().split())
if h == 1 or w == 1:
    print(1)
else:
    print(-(-(h * w) // 2))

Submission status: Accepted

Solution code:
a, b = map(int, input().split())
if a == 1:
  out = 1
elif b == 1:
  out = 1
elif a+b % 2 == 0:
  out = int(a*b/2)
else:
  out = int((a*b+1)/2)
print (out)

Submission status: Accepted

Solution code:
#!/usr/bin/env python3
h, w = map(int, input().split())
if h == 1 or w == 1:
    print(1)
    exit()
print(((h + 1) // 2) * ((w + 1) // 2) + (h // 2) * (w // 2))

Submission status: Accepted

Solution code:
H,W = map(int, input().split())
if H==1 or W==1:
  print(1)
else:
  print(-(-(H*W)//2))

Submission status: Accepted

Solution code:
h,w=map(int,input().split())
if h==1 or w==1:
 print(1)
else:
 print(((h+1)//2)*((w+1)//2)+(h//2)*(w//2))

Submission status: Accepted

Solution code:
H,W=list(map(int,input().split()))
HW=H*W
if H==1 or W==1:
    print(1)
else:
    if HW%2==0:
        print(int(HW/2))
    else:
        print(int(HW/2)+1)

Submission status: Accepted

Solution code:
# N = int(input())
# A = list(map(int, input().split()))
H, W = map(int, input().split())

if H == 1 or W == 1 :
  print(1)
  exit()

print(-(-(H * W) // 2))

Submission status: Accepted

Solution code:
import math
H, W = map(int, input().split())
if H == 1 or W == 1:
    print(1)
elif H % 2 == 1 and W % 2 == 1:
    print(math.ceil(H*W/2))
else:
    print(int(H*W/2))

Submission status: Accepted

Solution code:
h, w = map(int, input().split())

a = h * w

if h == 1 or w == 1:
    print(1)
    exit()

if a % 2 == 0:
    print(a//2)
else:
    print(a//2 + 1)

Submission status: Accepted

Solution code:
from math import ceil


def main():
    h, w = map(int, input().split())
    print(w * (h // 2) + ceil(w / 2) * (h % 2) if h > 1 and w > 1 else 1)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import math
a, b = list(map(int, input().split()))

if a == 2 and b == 2:
    print(1)
    exit() 
if a == 1 or b == 1:
    print(1)
    exit() 
r = math.ceil(a*b/2)
print(r)

Submission status: Accepted

Solution code:
#!/usr/bin/env python

h, w = (int(val) for val in input().split())
t = int((h * w + 1) / 2)
if h == 1 or w == 1:
    t = 1
print(t)

Submission status: Accepted

Solution code:
h,w = map(int,input().split())
c = h*w
if h==1 or w==1:
    ans = 1
elif c%2==0:
    ans = c/2
else:
    ans = c/2+1
print(int(ans))

Submission status: Accepted

Solution code:
a, b = map(int, input().split())

n = a*b

if a == 1 or b == 1:
    print(1)
elif n % 2 == 1:
    print(n//2 + 1)
else:
    print(n//2)

Submission status: Accepted

Solution code:
import queue
import math
import copy
"""
N = int(input())
#S = input()
# (N,M) = (int(i) for i in input().split(" "))
# A = [int(i) for i in input().split()]
A = []
for i in range(N):
	A.append(int(input()))

print(A)

"""
(N,M) = (int(i) for i in input().split(" "))
if N==1 or M==1:
	print(1)
else:
	S = N%2 + M%2
	T = (N-N%2)*(M-M%2)//2
	if N%2:
		T += (M+1)//2
	if M%2:
		T += (N+1)//2
	if S == 2:
		T -= 1
	print(T)

Submission status: Accepted

Solution code:
H,W = [int(i) for i in input().split()]

if (H ==1) | (W ==1):
 	ans = 1
  
elif (H%2 ==1) & (W%2==1):
    ans = int(H*W//2 +1)
else:
    ans = int(H*W/2)
    
print(ans)

Submission status: Accepted

Solution code:
a,b = map(int,input().split())
menseki = a*b
if a == 1 or b == 1:
    ans = 1
else:
    ans = menseki // 2 + menseki % 2
print(ans)

Submission status: Accepted

Solution code:
class Solution:
    def solve(self, H: int, W: int) -> int:

        if H == 1 or W == 1:
            return 1
        else:
            return (H*W + 1) // 2


if __name__ == '__main__':

    # standard input
    H, W = map(int, input().split())

    # solve
    solution = Solution()
    print(solution.solve(H, W))

Submission status: Accepted

Solution code:
a=input().split(" ")
b=int(a[0])*int(a[1])
if int(a[0])==1 or int(a[1])==1:
    print(1)
else:
    if b%2==0:
        print(b//2)
    else:
        print(b//2+1)

Submission status: Accepted

Solution code:
import itertools
from collections import deque,defaultdict,Counter
from itertools import accumulate
import bisect
from heapq import heappop,heappush,heapify
from fractions import gcd
from copy import deepcopy
import math
import queue
#import numpy as np
#import sympy as syp(素因数分解とか)
Mod = 1000000007
import sys
sys.setrecursionlimit(100000) 
  
def sieve_of_eratosthenes(n):
    if not isinstance(n,int):
        raise TypeError("n is not int")
    if n<2:
        raise ValueError("n is not effective")
    prime = [1]*(n+1)
    for i in range(2,int(math.sqrt(n))+1):
        if prime[i] == 1:
            for j in range(2*i,n+1):
                if j%i == 0:
                    prime[j] = 0
    res = []
    for i in range(2,n+1):
        if prime[i] == 1:
            res.append(i)
    return res

 
class UnionFind:
    def __init__(self,n):
        self.parent = [i for i in range(n+1)]
        self.rank = [0 for i in range(n+1)]
    
    def findroot(self,x):
        if x == self.parent[x]:
            return x
        else:
            y = self.parent[x]
            y = self.findroot(self.parent[x])
            return y
    
    def union(self,x,y):
        px = self.findroot(x)
        py = self.findroot(y)
        if px < py:
            self.parent[py] = px
        else:
            self.parent[px] = py
 
    def same_group_or_no(self,x,y):
        return self.findroot(x) == self.findroot(y)

def main(): #startline--------------------------------------------
    h,w = map(int,input().split())
    if not (h == 1 or w == 1): 
        print(h*w // 2 if h % 2 == 0 or w % 2 == 0 else h*w // 2 + 1)
    else:
        print(1)
if __name__ == "__main__":
    main() #endline===============================================

Submission status: Accepted

Solution code:
H, W = map(int, input().split())

if H == 1 or W == 1:
    print(1)
    exit()
    
print(-(-H // 2) * -(-W // 2) + (H // 2) * (W // 2))