Problem:
 Score : 100 points    Problem Statement There is a right triangle ABC with ∠ABC=90° .  Given the lengths of the three sides, |AB|,|BC| and |CA| , find the area of the right triangle ABC .  It is guaranteed that the area of the triangle ABC is an integer.      Constraints  1 \leq |AB|,|BC|,|CA| \leq 100  All values in input are integers.  The area of the triangle ABC is an integer.         Input Input is given from Standard Input in the following format:  |AB|  |BC|  |CA|       Output Print the area of the triangle ABC .        Sample Input 1 3 4 5      Sample Output 1 6   This triangle has an area of 6 .       Sample Input 2 5 12 13      Sample Output 2 30  This triangle has an area of 30 .       Sample Input 3 45 28 53      Sample Output 3 630  This triangle has an area of 630 .

Solution (Python):
ab, bc, ca = map(int, input().split())

print(int(ab*bc/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b/2))

Solution (Python):
a ,b, c = [int(x) for x in input().split()]
print(int(a*b/2))

Solution (Python):
list1 = [int(a) for a in input().split()]
list1_0 = list1[0] 
list1_1 = list1[1] 
list1_2 = list1[2] 

if (list1_0 * list1_1 // 2) > 1:
    print(list1_0 * list1_1 // 2)
else:
    print(list1)

Solution (Python):
def solve(string):
    l = sorted(map(int, string.split()))
    return str(l[0] * l[1] // 2)


if __name__ == '__main__':
    print(solve(input()))

Solution (Python):


AB, BC, CA = map(int, input().split())

print(int(AB*BC/2))

Solution (Python):
E = list(map(int, input().split()))

print(int(E[0]*E[1]/2))

Solution (Python):
L = list(map(int, input().split()))
L.sort()
Area = int(L[0]*L[1]/2)
print(Area)

Solution (Python):
A = [int(n) for n in input().split()]
print(int(A[0]*A[1]/2))

Solution (Python):
a,b,c=map(int,input().split())
print(str(int(0.5*a*b)))

Solution (Python):
ab,bc,ca = list(map(int, input().split()))
print(ab*bc//2)

Solution (Python):
a, b, c = map(int, input().split())
print(a * b // 2)

Solution (Python):
x, y,z = [int(i) for i in input().split()]

print(int(x*y/2))

Solution (Python):
a,b,c = map(int,input().split())
print(a*b//2)

Solution (Python):
AB, BC, CA = map(int, input().split())
print(int(AB*BC/2))

Solution (Python):
ri = lambda: int(input())
rl = lambda: list(map(int,input().split()))

x,y,z =rl()
print(x*y//2)

Solution (Python):
A, B, C = map(int,input().split())
print(int(A*B/2))

Solution (Python):
ri = lambda: int(input())
rl = lambda: list(map(int,input().split()))

x,y,z = rl()

print(int(x*y/2))

Solution (Python):






l = [int(x) for x in input().split()]





print(int(l[0]*l[1]/2))

Solution (Python):
A,B,C=map(int,input().split())
print(A*B//2)

Solution (Python):
hen_list = list(map(int,input().split()))

sorted_hen_list = sorted(hen_list)
menseki = sorted_hen_list[0]*sorted_hen_list[1]//2
print(menseki)

Solution (Python):
a,b,c = map(int,input().split())
print(int(a*b/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
import math
x,y,z=map(int,input().split())
S=round(x*y/2)
print(S)

Solution (Python):
AB,BC,CA = map(int,input().split())
print(int(AB * BC / 2))

Solution (Python):
e = [int(x) for x in input().split()]
print(e[0]*e[1]//2)

Solution (Python):

"""
"""

from collections import defaultdict
import sys

import math


def sol(a, b, c):
    return int(a * b / 2)


do_submit = True


def input_parse(input_str):
    lines = [x.strip() for x in input_str.split("\n") if x.strip()]
    parsed_lines = [list(map(int, line.split())) for line in lines]
    a, b, c = parsed_lines[0]
    return a, b, c


if not do_submit:
    a, b, c = input_parse("""
    45 28 53
    """)
    print(sol(a, b, c))
else:
    a, b, c = list(map(int, input().split()))
    print(sol(a, b, c))

Solution (Python):
x,y,z = map(int,input().split())
print(x * y // 2)

Solution (Python):
x,y,z = map(int,input().split())
print(x * y // 2)

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

if a**2+b**2 == c**2:
    print(int(a*b/2))
elif b**2+c**2 == a**2:
    print(int(b*c/2))
else:
    print(int(c*a/2))

Solution (Python):
ab,bc,ca = map(int,input().split())

print(int(ab*bc/2))

Solution (Python):
a,b,c=map(int, input().split())
print(a*b//2)

Solution (Python):
AB, BC, CA = list(map(int,input().split()))
print( int( AB * BC / 2) )

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

print(int(a * b / 2))

Solution (Python):
li = list(map(int, input().split()))

print(int(li[0] * li[1] / 2))

Solution (Python):
a,b,c = map(int,input().split())
print(int(a*b/2))

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

menseki = int(a * b / 2)
print(menseki)

Solution (Python):
a, b, c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
X = list(map(int, input().split()))
X.sort()
print(int(0.5*X[0]*X[1]))

Solution (Python):
ab, bc, ca = map(int, input().split())
print(int(bc*ab/2))

Solution (Python):



ab, bc, ca = map(int,input().split())

res = ab * bc / 2

print("%d" % res)

Solution (Python):
a, b, c = map(int, input().split())
print(a*b//2)

Solution (Python):
ab, bc, ca = map(int, input().split())
print(ab * bc // 2)

Solution (Python):
a_b, b_c, c_a = map(int, input().split())
if (a_b**2 + b_c**2) == c_a**2:
    print(int(a_b * b_c /2))
else:
    print('直角三角形ではない')

Solution (Python):
l=list(map(int,input().split()))
p=l[0]*l[1]/2
print(int(p))

Solution (Python):
ab, bc, ac = map(int, input().split(' '))
print(int(ab * bc * 0.5))

Solution (Python):
import sys
A,B,C = [int(n) for n in input().split()]






print(int(A*B/2))

Solution (Python):
import math
a,b,c = map(int,input().split())

result = (a*b)/2
print(math.floor(result))

Solution (Python):
i = list(map(int, input().split())) 
print(int((i[0] * i[1]) / 2))

Solution (Python):
ab, bc, cd = map(int, input().split())

print(int(ab*bc/2))

Solution (Python):
c,a,b=map(int,input().split())
print(int(c*a/2))

Solution (Python):
a,b,c=map(int,input().split())
print((a*b)//2)

Solution (Python):
ab, bc, ac = [int(i) for i in input().split()]
print(ab * bc // 2)

Solution (Python):
ab,bc,ca = map(int,input().split())
print(int((ab*bc)/2))

Solution (Python):
AB, BC, CA = map(int, input().split())
print(int(AB * BC / 2))

Solution (Python):
a, b, c = map(int, input().split())
print(a * b // 2)

Solution (Python):

import math
a, b, c = map(int, input().split())

s = (a + b + c)/2

print(int(math.sqrt(s*(s-a)*(s-b)*(s-c))))

Solution (Python):
S = list(map(int,input().split()))
AB = S[0]
BC = S[1]
CA = S[2]

answer = AB * BC // 2

print(answer)

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

print(a * b // 2)

Solution (Python):
a, b, c= map(int, input().split())
print(int(a*b/2))

Solution (Python):
ab, bc, ca = map(int, input().split())
print(int(ab * bc / 2))

Solution (Python):
AB, BC, CA = map( int, input().split() )

print( int(AB*BC/2) )

Solution (Python):
AB, BC, CA = map(int, input().split())

print((AB * BC) // 2)

Solution (Python):
a,b,c=list(map(int,(input()).split()))
print (int(((a)*(b))/2))

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b/2))

Solution (Python):
a, b, c = map(int, input().split())
print(a * b //2)

Solution (Python):
def calc_area(w, h):
        return w * h // 2


w, h, _ = [int(v) for v in input().split()]
print(calc_area(w, h))

Solution (Python):


A, B, C = map(int, input().split())

print(int(A*B/2))

Solution (Python):
x, y, z = map(int, input().split())
print(int(x * y / 2))

Solution (Python):
a = raw_input()
values = a.split(" ")
values = [int(i) for i in values]
m = max(values)
values = [i for i in values if i!=m]
print(values[0]*values[1]/2)

Solution (Python):
import math
a, b, c = map(int, input().split())
s = (a + b + c)/2
S = math.sqrt(s*(s-a)*(s-b)*(s-c))
print(int(S))

Solution (Python):
l = sorted(list(map(int, input().split())))
print(int(l[0]*l[1]/2))

Solution (Python):
ab,bc,ca = map(int,input().split())
print(int(ab*bc/2))

Solution (Python):
a,b,c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
A, B, C = map(int, input().split())
print(int(A*B/2))

Solution (Python):
from functools import reduce
from operator import mul

def solve():
	L = [int(i) for i in input().split()]
	return reduce(mul, L) // (2 * max(L))

print(solve())

Solution (Python):
a,b,c=map(int,input().split());print(a*b//2)

Solution (Python):
a,b,c = list(map(int,input().split()))
print(int(a*b/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
AB,BC,CA = map(int,input().split())
print(AB*BC//2)

Solution (Python):
inp = input().split(" ")
a = int(inp[0])
b = int(inp[1])
print(int(a*b/2))

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

print(a*b//2)

Solution (Python):
L = list(map(int, input().split()))

L.remove(L[L.index(max(L))])
S = 1
for i in range(2):
  S *= L[i]
  
print(S//2)

Solution (Python):
a, b, c = map(int, input().split())
print(int(a * b / 2))

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

print(a*b//2)

Solution (Python):
a, b, c = map(int, input().split())
print(min([a*b, b*c, c*a]) // 2)

Solution (Python):
l = sorted(list(map(int,input().split())))
print(l[0]*l[1]//2)

Solution (Python):




def main():
    x, y, z = map(int, input().split())
    print(x*y//2)


if __name__ == '__main__':
    main()

Solution (Python):
ab, bc, ca = map(int, input().split())

print(ab * bc // 2)

Solution (Python):
sides = raw_input()
sides = [int(i) for i in sides.split(" ")]
m = max(sides)
sides = [i for i in sides if i!=m]
print(sides[0]*sides[1]/2)

Solution (Python):



def main():
    s = input()
    ret = solve(s)
    print(ret)


def solve(s):
    ary = list(map(int, s.split()))
    ary.sort()
    return ary[0] * ary[1] // 2


main()

Solution (Python):
a, b, _ = map(int, input().split())
print(a*b//2)

Solution (Python):
a, b, c = map(int,input().split())
print((a*b)//2)

Solution (Python):
a,b,c=map(int,input().split())
print(a*b*c//(2*max(a,b,c)))

Solution (Python):


a,b,c = map(int,input().split(" "))
print(round(a*b/2))

Solution (Python):
x,y,z= map(int,input().split())
print(int(x*y/2))

Solution (Python):
s = input().split()
s = [int(i) for i in s]
print(int(s[0]*s[1]/2))

Solution (Python):

v = sorted([int(x) for x in input().split()])

print( int(0.5 * v[0] * v[1]))

Solution (Python):
a, b, c = map(int, input().split())
print(int(a*b/2))

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

print(round(a * b * (1/2)))

Solution (Python):
[c,b,a] = [int(i) for i in input().split()]
print(int(c*b/2))

Solution (Python):
a,b,c = map(int,input().split())
print(int(a*b/2))

Solution (Python):
import math

a, b, c = map(int, input().split())

s = (a + b + c) / 2

print(int(math.sqrt(s * (s - a) * (s - b) * (s - c))))

Solution (Python):
a, b, c = map(int ,input().split())
print((a*b)//2)

Solution (Python):
a,b,c = map(int,input().split())
print(a*b//2)

Solution (Python):
lines = list(map(int, input().split()))
lines.sort()
 
print((lines[0] * lines[1]) // 2)

Solution (Python):
x = list(map(int, input().split()))
print(int(x[0] * x[1] / 2))

Solution (Python):
a, b, c = map(int, input().split())
print(a * b // 2)

Solution (Python):
n = list(map(int,input().split()))
n = sorted(n)
print(int(n[0]*n[1]/2))

Solution (Python):
abc = sorted(list(map(int, input().strip().split())))
print(abc[0] * abc[1] // 2)

Solution (Python):
n,m,p = map(int,input().split())
print(int(n*m/2))

Solution (Python):
ab, bc, ca = map(int, input().split(' '))
print('%d' % (ab * bc / 2))

Solution (Python):
a,b,c = map(int, input().split( ))
area = int(a*b /2)
print(area)

Solution (Python):
s=list(map(int,input().split()))
p=sorted(s)
print(p[0]*p[1]//2)

Solution (Python):
a, b, c = map(int, input().split())
print(int(a * b / 2))

Solution (Python):
c, a, _ = map(int, input().split())
print(int(c * a / 2))

Solution (Python):
L = [int(x) for x in input().split()]
L.sort()
print(L[1] * L[0] // 2)

Solution (Python):

A,B,C = map(int, input().split())

print(int(A*B/2))

Solution (Python):
A, B, C = map(int, input().split())
print(min(A, B, C)*(A+B+C-max(A, B, C)-min(A, B, C))//2)

Solution (Python):
ab, bc, ca = map(int,input().split())

print(int(ab * bc / 2))

Solution (Python):
a, b, c = [int(_) for _ in input().split()]
print(int(a * b / 2))

Solution (Python):
AB,BC,CA = map(int, input().split())
print(int(AB*BC/2))

Solution (Python):
a,b,c = map(int, input().split())
print(a*b//2)

Solution (Python):
ab, bc, ca = map(int, input().split())

print(int(ab*bc/2))

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

hect = int(a*b*0.5)
print(hect)

Solution (Python):
from collections import defaultdict, Counter
from itertools import product, groupby, count, permutations, combinations
from math import pi, sqrt
from collections import deque
from bisect import bisect, bisect_left, bisect_right
from string import ascii_lowercase
from functools import lru_cache
import sys
sys.setrecursionlimit(10000)
INF = float("inf")
YES, Yes, yes, NO, No, no = "YES", "Yes", "yes", "NO", "No", "no"
dy4, dx4 = [0, 1, 0, -1], [1, 0, -1, 0]
dy8, dx8 = [0, -1, 0, 1, 1, -1, -1, 1], [1, 0, -1, 0, 1, 1, -1, -1]


def inside(y, x, H, W):
    return 0 <= y < H and 0 <= x < W


def ceil(a, b):
    return (a + b - 1) // b



def gcd(a, b):
    if b == 0:
        return a
    return gcd(b, a % b)


def lcm(a, b):
    g = gcd(a, b)
    return a / g * b


def main():
    AB, BC, CA = map(int, input().split())
    print(AB * BC // 2)


if __name__ == '__main__':
    main()

Solution (Python):
A, B, C = map(int, input().split())
print(A * B // 2)

Solution (Python):
ab, bc, ca = map(int, input().split())
print(int(ab*bc*0.5))

Solution (Python):
AB, BC, CA = [int(data) for data in input().split()]
print(int(AB*BC / 2))

Solution (Python):
l = [int(i) for i  in input().split()]
print(int(l[0]*l[1]/2))

Solution (Python):
a, b, c = map(int, input().split())
print(int(a * b /2))

Solution (Python):



def main():
    a, b, hypo = map(int, input().split())

    print(a*b//2)


if __name__ == '__main__':
    main()

Solution (Python):
AB, BC, CA = (int(i) for i in input().split())

print(int(AB*BC*CA /(2*(max(AB,BC,CA)))))

Solution (Python):
a,b,c = map(int,input().split())
print(int((a*b)/2))

Solution (Python):
a, b, c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
a,b,c=map(int, input().split())
print(a*b//2)

Solution (Python):

xlist = list(map(int,input().split()))

S = xlist[0]*xlist[1]/2
print(int(S))

Solution (Python):
AB,BC,CA=map(int,input().split())
print(int(AB*BC/2))

Solution (Python):

from sys import stdin


s_in = lambda: stdin.readline()[:-1]  
d_in = lambda: int(stdin.readline())  
ds_in = lambda: list(map(int, stdin.readline().split()))  

a, b, c = ds_in()
print(a * b // 2)

Solution (Python):
a,b,c = map(int,input().split())
print(int(a*b/2))

Solution (Python):
a,b,c = (int(i) for i in input().split())
print(( a * b ) // 2 )

Solution (Python):
h,b,c =  map(int,input().split())
sum = h * b /2
print(round(sum),end="")

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b/2))

Solution (Python):
a_b, b_c, c_d = map(int, input().split())
print(int(a_b * b_c / 2))

Solution (Python):
import heapq

inputs = list(map(int, input().split()))
a, b = heapq.nsmallest(2, inputs)

print(a * b // 2)

Solution (Python):
a,b,c = map(int,input().split())
print(a*b//2)

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b/2))

Solution (Python):

a,b,c=map(int,raw_input().split())
print a*b/2

Solution (Python):
x,y = [int(i) for i in input().split()[:2]]
print(int(x*y/2))

Solution (Python):
ab, bc, ca = map(int, input().split())

print((bc * ab) // 2)

Solution (Python):
a,b,c = map(int, input().split())
print(a*b//2)

Solution (Python):
a,b,c = map(int,input().split(" "))
print((a * b) // 2)

Solution (Python):
list = list(map(int, input().split()))

ab = list[0]
bc = list[1]
ac = list[2]

print(int(0.5*ac*bc*ab/ac))

Solution (Python):
T = input().rstrip().split(" ")

AB=int(T[0])
BC=int(T[1])
menseki = (AB * BC )/2
print(int(menseki))

Solution (Python):
items = sorted(list(map(int,input().split())))
print(int(items[0]*items[1]/2))

Solution (Python):
import sys
input = sys.stdin.readline

a, b, c = [int(i) for i in input().split()]
print(int(a*b/2))

Solution (Python):
A,B,C=map(int,input().split(" "))
print(A*B//2)

Solution (Python):
a, b, c = [int(i) for i in input().split()]
print(int(a * b / 2))

Solution (Python):
l=list(map(int,input().split()))
l.sort()
print(int((l[0]*l[1])/2))

Solution (Python):
n = list(map(int,input().split()))
print(int(0.5*n[0]*n[1]))

Solution (Python):
a = sorted(map(int, input().split()))

print(int((a[0]*a[1])/2))

Solution (Python):
l,n,m=map(int,input().split())
print(int(l*n/2))

Solution (Python):
a,b,c = map(int,input().split())
Area = ( a*b ) // 2
print(Area)

Solution (Python):
a,b,c = map(int,input().split())
s = int((a+b+c)/2)
print(int((s*(s-a)*(s-b)*(s-c))**0.5))

Solution (Python):
edges = list(map(int , input().split()))
edges.sort()

print(edges[0] * edges[1] // 2)

Solution (Python):
a = input().split()
b = []
for i in a:
    b.append(int(i))
b.sort()
print(int(b[0] * b[1] / 2))

Solution (Python):
ab, bc, ac = map(int,input().split())
print(int((ab*bc)/2))

Solution (Python):
inp = [int(x) for x in input().split(" ")]
print(int(inp[0]*inp[1]/2))

Solution (Python):
from sys import stdin






n = stdin.readline().split()
a = int(n[0])
b = int(n[1])
c = int(n[2])


out = int(a * b /2)

print(out)

Solution (Python):
a = list(map(int, input().split()))
a.sort()
print(a[0]*a[1]//2)

Solution (Python):
a, b, c = sorted([int(i) for i in input().split()])
print(a * b // 2)

Solution (Python):
import math
import sys
from operator import itemgetter








a, b, c = map(int, input().split())
print(a*b//2)

Solution (Python):
ab, bc, ca = list(map(int, input().split())) 
print(int(ab*bc / 2))

Solution (Python):
A, B, C = map(int,input().split())
print(A*B//2)

Solution (Python):
a,b,c = [int(x) for x in input().split()]
s = int(a * b / 2)
print(s)

Solution (Python):
ab, bc, _ = map(int, input().split())
print(ab * bc // 2)

Solution (Python):
a,b,_ = map(int,input().split())
print(a*b//2)

Solution (Python):
s = input().split(" ")
item = [int(i) for i in s]
item.sort()
print(int(item[0] * item[1] / 2))

Solution (Python):



if __name__=='__main__':
  li = [int(x) for x in input().split()]
  li.sort()
  print(int(li[0]*li[1]/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

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

t = max(a,max(b,c))

print((a*b*c)//(2*t))

Solution (Python):
a, b, c = [int(n) for n in input().split()]

print(a * b // 2)

Solution (Python):
def main():
    ab, bc, ca = map(int, input().strip().split(" "))
    area = int(ab*bc/2)
    print("{:d}".format(area))

if __name__ == "__main__":
    main()

Solution (Python):
a = list(int(i) for i in input().split())
print(a[0]*a[1]//2)

Solution (Python):
a = list(int(i) for i in input().split())
print(a[0]*a[1]//2)

Solution (Python):
AB, BC, CA = map(int,input().split())
print(int(AB * BC / 2))

Solution (Python):
in1 = list(map(int ,input().split(" ")))
in1.sort()
print(int((in1[0] * in1[1])/2))

Solution (Python):
arr = [int(i) for i in input().split()]

s = max(arr)
arr.remove(s)
print(int(arr[0] * arr[1] / 2))

Solution (Python):



ab, bc, ca = map(int, raw_input().split())
print ab*bc/2

Solution (Python):
import sys
 
for line in sys.stdin:
  nbs = line.split(' ')
  print(int(nbs[0]) * int(nbs[1]) // 2)

Solution (Python):


INPUT = input().split()

print(int(int(INPUT[0])*int(INPUT[1]) / 2))

Solution (Python):
I = [int(i) for i in input().split()]
I.sort()
ans = I[0] * I[1] // 2
print(ans)

Solution (Python):
ab, bc, ca = map(int, input().split())
print(ab * bc // 2)

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

print(a * b // 2)

Solution (Python):
i = list(map(int, input().split(" ")))

s = int(i[0] * i[1] / 2)

print(s)

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

if(a**2+b**2==c**2):
    print(int(a*b/2))
elif(b**2+c**2==a**2):
    print(int(b*c/2))
else:
    print(int(c*a/2))

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b*0.5))

Solution (Python):
A = list(map(int, input().split()))

A.sort()

print(A[0] * A[1] // 2)

Solution (Python):
a,b,c = map(int,input().split())
print(int(a*b/2))

Solution (Python):
def main():
    ab, bc, ca = map(int, input().split())
    print(ab * bc // 2)


if __name__ == '__main__':
    main()

Solution (Python):
import sys
input = sys.stdin.readline

AB, BC, CA = map(int, input().split())
print(int(0.5 * AB * BC))

Solution (Python):
AB, BC, CA = map(int, input().split())
print(int(0.5 * AB * BC))

Solution (Python):



a, b, c = map(int, raw_input().split())
print a*b /2

Solution (Python):
ab,bc,ca=map(int,input().split())
ans=int(ab*bc/2)
print(ans)

Solution (Python):
ab, bc, ca = list(map(int, input().split()))
area_of_triangle = int(round(ab*bc/2))
print(area_of_triangle)

Solution (Python):
import numpy as np

if __name__ == '__main__':
    a,b,c = map(int, input().split())
    print(int(a*b/2))

Solution (Python):
a, b, c = map(int, input().split())
print(int((a*b)/2))

Solution (Python):
x,y,z=list(map(int,input().split()))                              
print(int(x*y/2))

Solution (Python):
l = list(map(int, input().split()))
l.sort()
print(l[0] * l[1] // 2)

Solution (Python):
c, a, b = map(int, input().split())
ans = int(c * a / 2)
print(ans)

Solution (Python):
ab, bc, ca = input().split()
result = int((int(ab) * int(bc)) / 2)
print(result)

Solution (Python):
a,b,c = input().split(" ")
a,b,c = int(a),int(b),int(c)
area = int(a*b*c/(max(a,b,c)*2))
print(area)

Solution (Python):
ab, bc, ca = [int(x) for x in input().split()]
print(int(ab * bc / 2))

Solution (Python):
a, b, c = map(int, input().split())
res = int(a*b/2)
print(res)

Solution (Python):
ab,bc,ca = map(int,input().split())
print(int(ab*bc/2))

Solution (Python):
a,b,c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
line = input().split()
w = int(line[0]) * int(line[1]) // 2
print(w)

Solution (Python):
ab, bc, ca = map(int, input().split())
area = int(ab * bc / 2)
print(area)

Solution (Python):
a,b,c = map(int,input().split())
print(b*a//2)

Solution (Python):
ab, bc, ca = map(int, input().split())
print((ab*bc)//2)

Solution (Python):
a, b, c =map(int,input().split())
print(int(a*b/2))

Solution (Python):

import heapq
a,b,c = [int(i) for i in input().split()]
tri=[a,b,c]
r= int(heapq.nsmallest(2,tri)[0]*heapq.nsmallest(2,tri)[1]/2)
print(r)

Solution (Python):
x = [int(i) for i in input().split()]
x.sort()
print(x[0]*x[1]//2)

Solution (Python):
ab, bc, ca = [int(i) for i in input().split()]
print((ab*bc)//2)

Solution (Python):
import math
V = [int(n) for n in input().split()]
s = sum(V) / 2
A = math.sqrt(s*(s-V[0])*(s-V[1])*(s-V[2]))
print(int(A))

Solution (Python):
a = list(map(int,input().split()))
aa = 1
for i in range(3):
  aa *= a[i]
  
print(aa//max(a)//2)

Solution (Python):
A,B,C=map(int, input().split())
print(int(A*B/2))

Solution (Python):
a, b, c = map(int, input().split())
print(int(a * b / 2))

Solution (Python):
ab,bc,ca=map(int,input().split())
print(int(ab*bc/2))

Solution (Python):
sides = sorted(map(int, input().split()))

a, b, _ = sides

print(a * b // 2)

Solution (Python):
a, b, _ = map(int, input().split())
print(a * b // 2)

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
ab, bc, ca = map(int,input().split())
print(int(ab*bc/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
c, a, b = map(int, input().split())
print(a * c // 2)

Solution (Python):
AB, BC, CA = map(int, input().split())
print(int((AB * BC) / 2))

Solution (Python):
l = raw_input().split()

l = map(lambda x: int(x), l)
l.sort()

print l[0] * l[1] / 2

Solution (Python):
a,b,c = map(int,input().split())
print(a*b*c//2//max(a,b,c))

Solution (Python):
inp = input().split()
print(int((int(inp[0]) * int(inp[1]) / 2)))

Solution (Python):
ab,bc,ca = map(int,input().split())
print(ab*bc // 2)

Solution (Python):
s = [int(i) for i in input().split()]
s.sort()
print(int(s[0]*s[1]/2))

Solution (Python):
A, B, _ = sorted(map(int, input().split()))

print(A * B // 2)

Solution (Python):


import sys, re
from collections import deque, defaultdict, Counter
from math import sqrt, hypot, factorial, pi, sin, cos, radians
from heapq import heappop, heappush, heapify, heappushpop
from bisect import bisect_left, bisect_right
from itertools import permutations, combinations, product
from operator import itemgetter, mul
from copy import deepcopy
from functools import reduce, partial
from fractions import Fraction
from string import ascii_lowercase, ascii_uppercase, digits

def input(): return sys.stdin.readline().strip()
def ceil(a, b=1): return int(-(-a // b))
def round(x): return int((x*2+1) // 2)
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
MOD = 10 ** 9 + 7

ab, bc, ca = MAP()

print(ab*bc//2)

Solution (Python):


def main():
    [AB, BC, CA] = list(map(int, input().split()))

    print(AB * BC // 2)


if __name__ == '__main__':
    main()

Solution (Python):
a=list(map(int,input().split()))
print('{:.0f}'.format(a[0]*a[1]/2))

Solution (Python):
ab, bc, ca = map(int, input().split())
print(ab * bc // 2)

Solution (Python):
AB, BC, CA = map(int, input().split())

print(AB*BC//2)

Solution (Python):
a, b, c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
a, b, c = map(int, input().split())
print(a * b //2)

Solution (Python):
c, a, b = map(int, input().split())
print(int(c * a / 2))

Solution (Python):
a, b, _ = sorted(map(int, input().split()))

print(a * b // 2)

Solution (Python):
ab, bc, ca = list(map(int, input().split()))
rec = ab * bc / 2
print (int(rec))

Solution (Python):
a, b, c = map(int, input().split())
sum_ = a * b / 2
print(int(sum_))

Solution (Python):
arr = sorted(list(map(int,input().split())))
print(int(arr[0]*arr[1]/2))

Solution (Python):
AB, BC, CA = map(int, input().split())
print((AB * BC) // 2)

Solution (Python):
sides = list(map(int,input().split()))
sides.remove(max(sides))
print(sides[0]*sides[1]//2)

Solution (Python):
l = list(map(int, input().split()))
a=l[0]*l[1]/2
print(int(a))

Solution (Python):
a, b, c = map(int, input().split())
print(a*b//2)

Solution (Python):
c, a, b = map(int, input().split())
S = a*c//2
print(S)

Solution (Python):
A,B,C = map(int,input().split())
print(int(A*B*0.5))

Solution (Python):
l = list(map(int, input().split()))
len=sorted(l)
print(int(len[1]*len[0]/2))

Solution (Python):
x = input()
y = x.split(" ")
triangle = [int(i) for i in y]
max_index = -1
max = 0
for line in range(len(triangle)):
    if(triangle[line] > max):
        max = triangle[line]
        max_index = line
del triangle[max_index]

print(int(triangle[0] * triangle[1] / 2))

Solution (Python):


l = list(map(int, input().split()))
l.sort()
print(int(l[0]*l[1]/2))

Solution (Python):
ab, bc, ca = map(int, input().split())
print(int(ab * bc / 2))

Solution (Python):
a,b,c = map(int, input().split())
print(int(a*b/2))

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

print(int(a * b / 2))

Solution (Python):
import math
a,b,c = map(int,input().split())
print(math.floor(a*b/2))

Solution (Python):
a,b,c=(map(int,input().split()))
print(a*b//2)

Solution (Python):
a = [int(i) for i in input().split()]
menseki = int(a[0]*a[1]/2)
print(menseki)

Solution (Python):
a, b, c = map(int, input().split())
print(a*b//2)

Solution (Python):
A, B, C = (int(x) for x in input().split())
print(A * B // 2)

Solution (Python):
a, b, c = map(int, input().split())
print(int(a*b/2))

Solution (Python):
a,b,c=map(int,input().split())
print(int(a*b/2))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):
x, y, z = input().split()

print(int(int(x) * int(y) / 2))

Solution (Python):
a,b,c=map(int,input().split(" "))
print(int(a*b/2))

Solution (Python):
A, B, C = map(int, input().split())

print(int(A * B / 2))

Solution (Python):


a = input().split(' ')

print(int(int(a[0]) * int(a[1]) / 2))

Solution (Python):
a,b,c=map(int,input().split());print(a*b//2)

Solution (Python):
a=sorted(list(map(int,input().split(" "))))
print(a[0]*a[1]//2)

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

print(a*b//2)

Solution (Python):
(a, b, c) = map(int, input().split(' '))
if a*a + b*b == c*c:
    print(a*b//2)
elif b*b + c*c == a*a:
    print(b*c//2)
elif c*c + a*a == b*b:
    print(c*a//2)

Solution (Python):
ab,bc,ca = map(int, input().split(" "))
A = int((ab*bc)/2)
print(A)

Solution (Python):
def area(ab, bc, ca):
  return int(ab * bc / 2)

s = input()
ab, bc, ca = map(lambda x: int(x), s.split())

print('%d' % area(ab, bc, ca))

Solution (Python):
a,b,c=map(int,input().split())
print(a*b//2)

Solution (Python):

a = list(map(int, input().split()))



a.sort()




print(int(a[0] * a[1] / 2))

Solution (Python):
a, b, c = map(int, input().split())
print(a*b*c//max(a, b, c)//2)

Solution (Python):
A, B, C = map(int, input().split())
print(A*B//2)

Solution (Python):
list=list(map(int,input().split()))
print(int(list[0]*list[1]/2))

Solution (Python):
a, b, c = map(int, input().split())
print((a*b)//2)

Solution (Python):
lst = list(map(int, input().split()))
lst.sort()
print(int(lst[0]*lst[1]*1/2))

Solution (Python):
from sys import stdin


def main():
    ab, bc, ca = [int(x) for x in stdin.readline().rstrip().split()]
    print(ab * bc // 2)


if __name__ == "__main__":
    main()

Solution (Python):
a, b, c = (int(i) for i in input().split(" "))
print(int(a * b / 2))

Solution (Python):
L = raw_input()
L = L.split()
for i, val in enumerate(L):
    L[i] = int(val)
L.sort()
S = int(L[0] * L[1] / 2)
print(S)

Solution (Python):
inline = list(map(int,input().split()))
sortinline = sorted(inline)
ans = sortinline[0] * sortinline[1] * 0.5
print(int(ans))

Solution (Python):
print((lambda x:x[0]*x[1]//2)(list(map(int,input().split()))))

Solution (Python):
A, B, _ = map(int, input().split(" "))

print(A*B//2)

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

print((int)(a*b/2))

Solution (Python):
x,y,z = map(int,input().split())
print(int(x*y/2))

Solution (Python):
a = list(map(int,input().split()))
print(a[0]*a[1]//2)

Solution (Python):
a, b, c= map(int, input().split())
print(a * b //2)

Solution (Python):





d = input().split()
a = d[0]
b = d[1]

print(int(int(a)*int(b)/2))

Solution (Python):
AB, BC, CA = map(int, input().split())
S = int(AB * BC /2)
print(S)

Solution (Python):
a, b ,c = list(map(int, input().split()))
print(int(a * b / 2))

Solution (Python):
a,b,c=map(int,input().split())
arr=sorted([a,b,c])
print(int(arr[0]*arr[1]/2))

Solution (Python):
a, b, c = map(int, input().split())
print(a * b // 2)