Python

# Python cheat-sheet (the bits you'll need)

# Comments start with #
print("hello")              # output
x = 42                      # variables — no type annotation needed
name = "ada"                # strings: "..." or '...'
pi = 3.14                   # floats
ok = True                   # booleans (True/False)
nothing = None              # null

# f-strings
print(f"x={x}, name={name}")

# Math
2 + 3        # 5
2 ** 8       # 256 (power)
7 // 2       # 3  (integer division)
7 % 2        # 1  (modulo)

# Conditions (indentation matters!)
if x > 0:
    print("positive")
elif x == 0:
    print("zero")
else:
    print("negative")

# Loops
for i in range(5):       # 0..4
    print(i)

while x > 0:
    x -= 1

# Lists / tuples / dicts / sets
nums = [1, 2, 3]
nums.append(4)
point = (1, 2)
person = {"name": "ada", "age": 36}
unique = {1, 2, 3}

# Comprehensions
squares = [n*n for n in range(5)]
evens = {n for n in nums if n % 2 == 0}
lookup = {n: n*n for n in range(5)}

# Functions
def add(a, b):
    return a + b

# Reading input from stdin
line = input()           # one line of input
n = int(input())         # parse to int