# Write a python function to find minimum number swaps required to make two binary strings equal.
def min_Swaps(s1, s2):
    c0 = 0
    c1 = 0
    for i in range(len(s1)):
        if s1[i] == "0" and s2[i] == "1":
            c0 += 1
        elif s1[i] == "1" and s2[i] == "0":
            c1 += 1
    result = c0 // 2 + c1 // 2
    if c0 % 2 == 0 and c1 % 2 == 0:
        return result
    elif (c0 + c1) % 2 == 0:
        return result + 2
    else:
        return -1
