def is_prime(n: int) -> bool:
if n < 2:
return False
if n % 2 == 0 and n != 2:
return False
i = 3
while i * i <= n:
if n % i == 0:
return False
i += 2
return True
def concat(a: int, b: int) -> int:
s = str(a) + str(b)
return int(s)
def main():
limit = 12 # you can increase this
primes = [i for i in range(2, limit + 1) if is_prime(i)]
# Check pairs
for i in range(len(primes)):
for j in range(len(primes)):
if i == j:
continue # skip same prime if you want
num = concat(primes[i], primes[j])
if is_prime(num):
print(f"{primes[i]} + {primes[j]} -> {num} is prime")
if __name__ == "__main__":
main()
'''
run:
2 + 3 -> 23 is prime
2 + 11 -> 211 is prime
3 + 7 -> 37 is prime
3 + 11 -> 311 is prime
5 + 3 -> 53 is prime
7 + 3 -> 73 is prime
11 + 3 -> 113 is prime
'''
