program oken; uses crt; var i,n,dem:integer; kt:boolean; begin clrscr; write('nhap n: '); readln(n); for i:=2 to n-1 do if n mod i =0 then dem :=dem+1; if dem=0 then kt:=true; if (n=0) or (n=1) or (dem>0) then kt:=false; if kt=true then writeln(n,' la so nguyen to') else writeln(n,' khong phai la so nguyen to'); readln; end.
