If the focal length of the ellipse x2m + y24 = 1 is 2, then the value of M is equal to______ .

If the focal length of the ellipse x2m + y24 = 1 is 2, then the value of M is equal to______ .

When the focus of the ellipse is on the x-axis, M-4 = 1, the solution is m = 5. When the focus of the ellipse is on the y-axis, 4-m-1, the solution is m = 3