Write a python function to find the first natural number whose factorial is divisible by x.
def first_Factorial_Divisible_Number(x): 
    i = 1;
    fact = 1; 
    for i in range(1,x): 
        fact = fact * i 
        if (fact % x == 0): 
            break
    return i 
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a python function to find the first natural number whose factorial is divisible by x.
def first_Factorial_Divisible_Number(x): 
    i = 1;
    fact = 1; 
    for i in range(1,x): 
        fact = fact * i 
        if (fact % x == 0): 
            break
    return i [/INST]assert first_Factorial_Divisible_Number(10) == 5
assert first_Factorial_Divisible_Number(15) == 5
assert first_Factorial_Divisible_Number(5) == 4</s>