var i,n,d:longint; begin read(n); for i := 1 to n do begin if n mod i = 0 then inc(d); end; if d = 2 then write(n,' la so nguyen to') else write(n,' khong phai la so nguyen to'); end.
Program SO_NGUYEN_TO; Uses crt; Var i,n: integer; Begin Clrscr; Writeln('KIEM TRA SO NGUYEN TO:'); Writeln('---------------------------'); Write ('Nhap so can kiem tra n = '); readln(n); If (n=0) or (n=1) then Writeln(n,' Khong phai la so nguyen to') Else Begin i:=1; Repeat i:= i+1; Until (n mod i= 0) or (i*i>n); If i*i>n then Writeln (n,' la so nguyen to') Else Writeln (n,' khong phai la so nguyen to');
