What is wrong with the matlab code here ? Can someone help me ? i using 2019 matlab

>> syms x y z; y = input ("enter your curve such that has only x terms:'); f = input('enter your function : '); disp (f); disp (y); x_ip = input ("enter your x inputs'); dy = diff(y,x); disp (dy); ds = sqrt (1+ (dy)^2); disp (ds); Integrand = f*ds; disp (Integrand); result = int (Integrand, x,x_ip (1,1),x_ip (1,2); disp (result); disp (eval (result)); y = input ("enter your curve such that has only x terms:'); 1 Error: Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII characters