def first_Repeated_Char(str):
     
    h = {}
    for ch in str:
        if ch in h: 
            return ch;
        else: 
            h[ch] = 0
    return '\0'
def is_not_prime(n):
    import math
    
    result = False
    for i in range(2,int(math.sqrt(n)) + 1):
        if n % i == 0:
            result = True
    return result