Срочно! 1Дано натур. Число

1.var a: longint; beginread (a); if (a mod 10)=(a div 10) mod 10) thenwriteln ('YES') elsewriteln ('NO'); end.2.var a,b,c: longint; beginread (a,b,c); if (a mod 2)=1 thena: =a*2; if (b mod 2)=1 thenb: =b*2; if (c mod 2)=1 thenc: =c*2; end.4var a,b,c: longint; begin for a: =21 to 99 do b: =b+a; writeln (b); end.5.var a,b: longint; function nod (a,b: longint): longint; var c,d: longint; beginwhile (a>0) or (b>0) do begin c: =a mod b; a: =c; if a=0 then break; d: =b mod a; b: =d; if b=0 then break; end; if d>0 thennod: =d elsenod: =c; if (a=b) or (a=1) or (b=1) thennod: =1; end; beginread (a,b); if a>=b thenwriteln (a*b div nod (a,b) else writeln (a*b div nod (b,a); end.