TONG1 PASCAL

var     s1,s2,s3:int64;
    i,n:longint;
begin
        assign(input, 'Tong1.inp');reset(input);
        assign(output,'Tong1.out');rewrite(output);
        read(n);
        //Tinh S1
        s1:=0;
        for i:=1 to n do
                s1:= s1+i;
        writeln('S1 = ',s1);
        // Tinh S2
        s2:=1;
        for i:=1 to n do
                s2:=s2*i;
        writeln('S2 = ',s2);
        // Tinh S3
        s3:=0;
        for i:=1 to n do
                s3 :=s3 + i*i;
        writeln('S3 = ',s3);
end.