def andProduct(a, b):
    
    if a == 0:
        return 0
    
    if a == b:
        return a
    
    out = None if a % 2 == 0 else a  
    
    
    if out is not None:
        a+=1 
        
    temp = a
    
    
    def check_less_significant_bits(num):
        
        shift = 0 
        zero=True 
        cum_sum=0
        
        n_sum=0
        
        
        while zero:
            zero = (num & ( 1 << shift )) == 0 
            if zero:
                cum_sum += 2**shift

            shift+=1
    
                
        return cum_sum + 1
            
    
    a += check_less_significant_bits(a)

    
    while a <= b:
        temp &= a 
        if temp == 0:
            return 0 
        
        inc = check_less_significant_bits(a)
        
        a+=inc
        
    
    if out is not None:
        return temp & out 
        
    return temp