Error while executing the code using simulink

So, I have written the code for filtering multiple noises using wiener filter. I was implementing the same using the matlab function block in the simulink. I got this code through matlab only.

so in the lines:

xest=xest(N+1:end)

MSE = mean(ecg(N+1:end) - xest) .^2;

plot(x(N+1:end),xest,'k')

in these 3 lines, I'am getting an error saying size mismatch, (size[1x5000] ~= size[1x?])

The dimensions of xest is 1x9700

could someone resolve this problem as soon as possible please

function xest  = fcn(noisy,ecg,N)
Fs = 500;
Ts = 1/Fs;
T=1;
x=0:Ts:10-Ts; 
L = T .* Fs; % signal length
tt = (0:L-1)/Fs; % time vector
ff = (0:L-1)*Fs/L;

X = 1/N .* fft(noisy(1:N));
Y = 1/N .* fft(ecg(1:N));
X = X(:);
Y = Y(:);
Rxx = N .* real(ifft( X.* conj(X))); % Autocorrelation function
Rxy = N .* real(ifft( X.* conj(Y))); % Crosscorrelation function
Rxx = toeplitz(Rxx);
Rxy = Rxy';
B = Rxy / Rxx; B = B(:); % Wiener-Hopf eq. B = inv(Rxx) Rxy
xest = fftfilt(B,x);
xest = xest(N+1:end); %cut first N samples due to distorsion during filtering operation
MSE = mean(ecg(N+1:end) - xest) .^2; % mean squared error
figure(3)
subplot(211)
plot(x,noisy,'r'), hold on, plot(x,ecg,'k')
subplot(212)
plot(x(N+1:end),xest,'k')
end