急急急!!如何用pascal来计算x-x的三次方/3的阶梯+x的5次方/5的阶梯……最后一项的绝对值小于10的（-7）次

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procedure jieti(a:integer):integer;
begin
...jieti:=1;
...for i:=1 to a do
......jieti:=jieti*a;
end;

read(x);
i:=1;
r:=0;//最后的结果
while not(abs(m)<=power(10,-7)) do
..begin
....m:=(power(x,(2*i-1)))/jieti((2*i-1)) *(-1)^(i+1);一项
....r:=r+m;加起来
....i:=i+1;
..end;
write(m);