In the below code segment I am trying to set a global variable called smallest to store the smallest number of coins which can form the amount. I am getting an error in the helper function while comparing num < smallest. It seems like it is accessing a local variable while I want to access a global variable.

cannot access local variable ‘smallest’ where it is not associated with a value

smallest = 98
def main():
    coins = [186,419,83,408]
    amount = 6249
    coinChange(coins, amount)
    print(smallest)
    
def coinChange(coins, amount):
    helper(coins, amount, 0)

def helper(coins, amount, num):
    if amount == 0:
        if num < smallest:
            smallest = num
        return
    if amount < 0:
        return
    for coin in coins:
        helper(coins, amount - coin, num + 1)

if __name__ == '__main__':
    main()```