Change values of a vector (SM to C2)

I don't know why my code doesn't work. My code suppose to de this:

It copys the bits of the vector from left to rigth until find the first 1. Then for the next bits I changes the 1s to 0s anf the 0s to 1s.

It is basically change from SM to C2.

Error: In an assignment A(:) = B, the number of elements in A and B must be the same.

V1(n) = 1-V1

In my code the vector that i want to make is [1 0 1 0]

CODE

V=[1 1 1 0]

V1 = fliplr(V) % 0 1 1 1

n=1;

x = 0;

while n<=length(V1)

if (V1(n) == 0 && x ~= 1) % If there is a 0 it keeps the (0)

V1(n) = 0

elseif (V1(n) == 1 && x ~= 1) % I keeps the fist (1)

V1(n)= 1

x = 1;

elseif x == 1 % When there has been a 1 i change the 0s to 1s and the 1s to 0s

V1(n) = 1-V1

end

n = n+1;

end

V1 = fliplr(V1)

V1 = [V(1) V1(2:4)] % [1 0 1 0]