def binary_sum(a: str, b: str) -> str:
    
    return bin(int(a, 2) + int(b, 2))[2:]

# Example usage
a1 = "11"
b1 = "1"
print(binary_sum(a1, b1)) 

a2 = "1010"
b2 = "1011"
print(binary_sum(a2, b2))