Fibonacci towers

MOD = 10**9 + 7  # Common modulo value for competitive programming

def binomial_mod(n, k, mod):
    """Computes C(n, k) % mod using modular arithmetic."""
    if k > n or k < 0:
        return 0
    
    # Compute combination using modular multiplicative inverse
    num, den = 1, 1
    for i in range(k):
        num = (num * (n - i)) % mod
        den = (den * (i + 1)) % mod
    
    # Fermat's little theorem for modular multiplicative inverse
    return (num * pow(den, mod - 2, mod)) % mod

def count_towers(a, b):
    """
    Count towers with specific constraints.
    
    Args:
    a (int): Base constraint
    b (int): Total height constraint
    
    Returns:
    int: Number of possible tower configurations
    """
    if b < a:
        return 0
    
    result = 0
    max_y = b // a  # Maximum value for y
    
    for y in range(max_y + 1):
        x = b - a * y
        if x < 0:
            break
        
        # Compute combinations and accumulate result
        result = (result + binomial_mod(x + y, x, MOD)) % MOD
    
    return result

# Example test cases
a, b = map(int, input().split())

# Compute and print the result
print(count_towers(a, b))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: TIME LIMIT EXCEEDED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: ACCEPTED

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: TIME LIMIT EXCEEDED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: WRONG ANSWER

Test 26

Verdict: ACCEPTED

Test 27

Verdict: WRONG ANSWER

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: WRONG ANSWER

Test 30

Verdict: TIME LIMIT EXCEEDED

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: WRONG ANSWER

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: WRONG ANSWER

Test 38

Verdict: ACCEPTED

Test 39

Verdict: WRONG ANSWER

Test 40

Verdict: TIME LIMIT EXCEEDED

Test 41

Verdict: TIME LIMIT EXCEEDED

Test 42

Verdict: TIME LIMIT EXCEEDED

Test 43

Verdict: TIME LIMIT EXCEEDED

Test 44

Verdict: TIME LIMIT EXCEEDED

Test 45

Verdict: TIME LIMIT EXCEEDED

Test 46

Verdict: TIME LIMIT EXCEEDED

Test 47

Verdict: TIME LIMIT EXCEEDED

Test 48

Verdict: TIME LIMIT EXCEEDED

Test 49

Verdict: TIME LIMIT EXCEEDED

Test 50

Verdict: TIME LIMIT EXCEEDED

Test 51

Verdict: TIME LIMIT EXCEEDED

Test 52

Verdict: TIME LIMIT EXCEEDED

Test 53

Verdict: TIME LIMIT EXCEEDED

Test 54

Verdict: TIME LIMIT EXCEEDED

Test 55

Verdict: TIME LIMIT EXCEEDED

Test 56

Verdict: TIME LIMIT EXCEEDED

Test 57

Verdict: TIME LIMIT EXCEEDED

Test 58

Verdict: TIME LIMIT EXCEEDED

Test 59

Verdict: TIME LIMIT EXCEEDED

Test 60

Verdict: TIME LIMIT EXCEEDED

Test 61

Verdict: TIME LIMIT EXCEEDED

Test 62

Verdict: TIME LIMIT EXCEEDED

Test 63

Verdict: TIME LIMIT EXCEEDED

Test 64

Verdict: TIME LIMIT EXCEEDED

Test 65

Verdict: TIME LIMIT EXCEEDED

Test 66

Verdict: TIME LIMIT EXCEEDED

Test 67

Verdict: TIME LIMIT EXCEEDED

Test 68

Verdict: TIME LIMIT EXCEEDED

Test 69

Verdict: TIME LIMIT EXCEEDED

Test 70

Verdict: TIME LIMIT EXCEEDED

Test 71

Verdict: TIME LIMIT EXCEEDED

Test 72

Verdict: TIME LIMIT EXCEEDED

Test 73

Verdict: TIME LIMIT EXCEEDED

Test 74

Verdict: TIME LIMIT EXCEEDED

Test 75

Verdict: TIME LIMIT EXCEEDED

Test 76

Verdict: TIME LIMIT EXCEEDED

Test 77

Verdict: TIME LIMIT EXCEEDED

Test 78

Verdict: TIME LIMIT EXCEEDED

Test 79

Verdict: TIME LIMIT EXCEEDED

Test 80

Verdict: TIME LIMIT EXCEEDED