program calc;
var
	num1,num2, action :integer;
    label 1;
begin
	1: writeln('write the first number');
    	readln(num1);
    writeln('write the second number');
    	readln(num2);
    writeln('pick the action you want to do:');
	writeln('1-Addition 2-Subtraction 3-Multiplication 4-Division');
    	read(action);
    		if action=1 then writeln(num1,'+',num2,'=',num1+num2);
            if action=2 then writeln(num1,'-',num2,'=',num1-num2);
            if action=3 then writeln(num1,'*',num2,'=',num1*num2);
            if action=4 then writeln(num1,'/',num2,'=',num1/num2);
            if action>4 then goto 1;
readln;
end.

case action of
  '1': Writeln(num1+num2);
  '2': Writeln(num1-num2);
  '3': Writeln(num1*num2);
  '4': Writeln(num1/num2);
  else goto 1;
end;

while keypressed do readkey;
readln;