program operators;
uses crt;
begin
 clrscr;
 writeln(17 div 3);
 readln;
 writeln(7 mod 4);
 readln;
end.

program posneg;
uses crt;
var 
 no : integer;
begin
 clrscr;
  Write('Enger a number:');
  readln(no);

  if (no > 0) then
   writeln('You enter Positive Number')
  else
    if (no < 0) then
     writeln('You enter Negative number')
    else
      if (no = 0) then
      writeln('You enter Zero');

  readln;
 end.

program lights;
uses crt;
var a,b:integer;
label 1;
begin
textbackground(white);
clrscr;
for a:=1 to 1000000 do inc b;
randomize;
1:
a:=random(4)+1;
if a=1 then textbackground(blue);
if a=2 then textbackground(red);
if a=3 then textbackground(green);
if a=4 then textbackground(yellow);
write(' ');
goto 1;
end.

program learn;
uses crt;
var a,b,c,e,f,right: integer; d:real;
label 1,2,3,4,5;
begin
textbackground(green);
textcolor(white);
clrscr;
repeat
inc(f);
until f=100000;
randomize;
1:
e:=random(3)+1;
b:=random(200)+1;
c:=random(200)+1;
if e=1 then d:=b+c;
if e=2 then d:=b-c;
if e=3 then d:=b*c;
writeln('  ',b:3);
if e=1 then write('+ ');  
if e=2 then write('- ');
if e=3 then write('x ');
writeln(c:3);
writeln('______');
readln(a);
if a=d then
begin                                       
inc(right);
writeln('HORRAY! YOU GOT IT RIGHT! you have ',right,' points!');
end
else
begin
right:=right-1;
writeln('WRONG! you have ',right,' points');
end;
goto 1;
end.

program veryweird;
uses crt;
type aaa=array[1..40,1..12] of char;
var a,b,c,d,e,pa,pd:integer; f:aaa; g:char;
label 1,2,3,4;
begin
pa:=1;
pd:=1;
writeln('hello');
writeln('press the arrow keys to move');
2:
IF KeyPressed THEN
BEGIN
g:=readkey;
CASE g OF
'H' :
begin
if pd=1 then goto 2; 
f[pa,pd]:='_';
pd:=pd-1;
f[pa,pd]:='@';
end;       
'K' :
begin
if pa=1 then goto 2;
f[pa,pd]:='_';
pa:=pa-1;
f[pa,pd]:='@';
end;
'M' :
begin
if pa=40 then goto 2;
f[pa,pd]:='_';
pa:=pa+1;
f[pa,pd]:='@';
end;
'P' :
begin
if pd=12 then goto 2;
f[pa,pd]:='_';
pd:=pd+1;
f[pa,pd]:='@';
end;
end;
clrscr;
for a:=1 to 12 do writeln(f[1,a],f[2,a],f[3,a],f[4,a],f[5,a],f[6,a],f[7,a],f[8,a],f[9,a],f[10,a],f[11,a],f[12,a],f[13,a],f[14,a],f[15,a],f[16,a],f[17,a],f[18,a],f[19,a],f[20,a],f[21,a],f[22,a],f[23,a],f[24,a],f[25,a],f[26,a],f[27,a],f[28,a],f[29,a],f[30,a],f[31,a],f[32,a],f[33,a],f[34,a],f[35,a],f[36,a],f[37,a],f[38,a],f[39,a],f[40,a]);
goto 2;
end
else goto 2;
end.