09. Sum of Two Numbers

first_num = int(input())
final_num = int(input())
magic_num = int(input())
combinations = 0
is_found = False
for i in range(first_num, final_num + 1):
    for j in range(first_num, final_num + 1):
        combinations += 1
        if i + j == magic_num:
            print(f'Combination N:{combinations} ({i} + {j} = {magic_num})')
            is_found = True
            break
    if is_found:
        break
if not is_found:
    print(f'{combinations} combinations - neither equals {magic_num}')

Или:

first_num = int(input())
final_num = int(input())
magic_num = int(input())
combinations = 0

for i in range(first_num, final_num + 1):
    for j in range(first_num, final_num + 1):
        combinations += 1
        if i + j == magic_num:
            print(f'Combination N:{combinations} ({i} + {j} = {magic_num})')
            exit(0)

print(f'{combinations} combinations - neither equals {magic_num}')