Леха:
program BTopoe_3adaHue;
uses crt;
var x:integer;
begin
clrscr;
write('x=');
readln(x);
if x<0 then write('sin(x)=-1') else
if x=0 then write('sin(x)=0') else
if x>0 then write('sin(x)=1');
readln;
end.

Коля:
program n9Toe_3adaHue;
uses crt;
var x,y:integer;
begin
clrscr;
writeln('x=');
readln(x);
writeln('y=');
readln(y);
if (x>0) and (y>0) then writeln('1') else
if (x<0) and (y>0) then writeln('2') else
if (x<0) and (y<0) then writeln('3') else
if (x>0) and (y<0) then writeln('4') else
if (x=0) then writeln('OCb y') else
if (y=0) then writeln('OCb x') else
writeln('Ha4aJlo KoopduHaT');
readln
end.

Света: \\пока под вопросом
program Bocbmoe_3adaHue;
uses crt;
var a:integer;
begin
clrscr;
writeln('rod?');
readln(a);
if a>10000 then writeln('AnokaJluncuc :( ') else
if (a mod 4=0) or (a mod 400=0) then writeln('YES') else writeln('NO');
readln
end.