var a: array [1… 100] of real; n, i: integer; begin read (n); for i: =1 to n do read (a[i]); for i: =1 to n do if a[i] <= 0 then begin writeln ('NO'); readln; Halt; end; writeln ('YES'); readln; end. var a: array [1… 100] of real; n, i: integer; o: real; begin read (n); for i: =1 to n do read (a[i]); o: =a[1]; for i: =2 to n do if a[i] <> o then begin writeln ('NO'); readln; Halt; end; writeln ('YES'); readln; end. var a: array [1… 100] of real; n, i: integer; x: real; begin read (n); for i: =1 to n do read (a[i]); read (x); for i: =1 to n do if a[i]=x then begin writeln ('YES'); readln; Halt; end; writeln ('NO'); readln; end.