Câu 1:
a,Var i,n,S:longint;
Begin
Read(S);
S:=0;
For i:=1 to n do S:=S+i;
Write(A);
Readln;
End.
b, Var S,n:longint;
Begin
S:=0; n:=0
While S<=1000 do
Begin n:=n+1; S:=S+n end;
Writeln('So n nho nhat de tong > 1000 là ' , n);
Writeln('tong dau tien > 1000 ' , S)
End.