Storing all Loop results in an array?

counter = 0;
max = 10;
UserInput = 1;
while(counter < max && UserInput == 1)
    A = input('\n Enter A value here ->');
    if (A < 0)
        fprintf ('\n \t ERROR: Enter A value that is more than zero, start again');
    elseif (A >= 0)
        fprintf ('\n \t Value Accepted! \n');
        
        B = input('\n Enter B value here ->');
        if (B < 0)
            fprintf ('\n \t ERROR: Enter B value that is more than zero, start again');
        elseif (B >= 0)
            fprintf ('\n \t Value Accepted! \n');
            C = A + B;
            %%I am trying to store the C  in an array for everytime the loop is ran
            fprintf('\n \t Result is %d \n', C)
            UserInput = input("\n Would you like to exit the program? [1 for no, 2 for yes] ->");
        end %For A loop
    end %For B loop 
end %For the while loop
fprintf('\n Goodbye \n')

Answer 1

[Matt J]

result(counter)=C;

[Grace]

Resulted in this error :Array indices must be positive integers or logical values.

[Walter Roberson]

counter = counter + 1;
result(counter) = C;