chapter 2:)
''' 4016 def idk(x, y, z): a = 0 if x>y: a = y else: a = x if a>z: a = z k = 0 for i in range(1, a+1): if x % i == 0 and y % i == 0 and z % i == 0: k=i print(k) a, b, c = input().split() a = int(a) b = int(b) c = int(c) idk(a, b, c) 4021 def idk(x): k = 0 for i in range(len(x)): if x[i] % 2 != 0: k += x[i] if k == 0: k = -1 print(k) arr = input().split() for i in range(len(arr)): arr[i] = int(arr[i]) idk(arr) 4026 def idk(x): x.sort() if len(x) % 2 != 0: print(x[len(x)//2]) else: w = x[len(x)//2] + x[len(x)//2 + 1] w = w /2 print(w) arr = input().split() for i in range(len(arr)): arr[i] = int(arr[i]) idk(arr) 4031 def idk(x): a = [] b = [] a.append(0) b.append(0) for i in range(len(x)): if x[i] % 2 == 0: a.append(x[i]) a.sort() n = a[-1] for i in range(len(x)): if x[i] % 2 != 0: b.append(x[i]) b.sort() m = b[-1] print(n + m) arr = input().split() for i in range(len(arr)): arr[i] = int(arr[i]) idk(arr) 4051 def idk(x): d = 0 for i in range(5): k = x[i][1] - x[i][0] if k <= 1: k = 0 else: k -= 1 if k > 4: k = 4 d += k k = d * 10000 if d >= 15: k = k * 0.95 elif d <= 5: k = k * 1.05 print(int(k)) n = [] for i in range(5): arr = input().split() for j in range(len(arr)): arr[j] = float(arr[j]) n.append(arr) idk(n) 4816 def idk(x): if x >= 300: a = x / 300 else: a = 0 if (x % 300) >= 60: b = (x % 300 )/ 60 else: b = 0 if (x % 300 ) % 60 >= 10: c = ((x % 300 ) % 60) / 10 else: c = 0 if (int(a)*300) + (int(b)* 60) + (int(c)*10) == x : print(int(a), int(b), int(c)) else: print('-1') n = int(input()) idk(n) '''