program ex27;
uses
sysutils;
var
numbers:array [1..2] of integer;
loopcounter, loopcounter1, i, loopcounter2, startat, answer, dummy : integer;
valid: boolean;
input : string;
procedure getinput; //WORKS
begin
//initialise
for i := 1 to 2 do
numbers[i]:= 0;
for loopcounter:=1 to 2 do
begin
repeat
write('Please enter the number: ');
readln(input);
valid:=true;
if length(input)=0 then
valid:=false
else
begin
if input[1]='-' then
startat:=2
else
startat:=1;
for loopcounter2:=startat to length(input) do
begin
if not (input[loopcounter2] in ['0'..'9']) then
valid:=false;
break;
end;
end;
if not valid then
writeln('this is not a valid integer.');
until valid;
numbers[loopcounter1]:=strtoint(input);
end;
end;
procedure calculatefibonacci(numbers: array of integer);
begin
for loopcounter:=1 to 2 do
dummy:=numbers[1]+numbers[2];
write(numbers[2]);
begin
answer:=numbers[1]+numbers[2];
writeln(answer);
writeln;
end;
end;
procedure closeprogram;
begin
write('Press enter to close');
readln;
end;
begin
getinput;
calculatefibonacci(numbers);
closeprogram;
end.