Function ngto(a: longint): boolean; Var i: longint; Begin If a<2 then exit(false); For i:=2 to a div 2 do If a mod i = 0 then exit(false); exit(true); End;
Begin Clrscr; Write('Nhap m: '); Readln(m); Write('Nhap n: '); Readln(n); d:=0; If m<=n then For i:=m to n do If ngto(i) then inc(d); If m>n then Write('Sai yeu cau de') Else Write('Co ',d,' so nguyen to'); Readln; End.
