```cpp
var n,n1,t:real;
s:longint;
begin
read(n);
n1:=2;
repeat
n1:=n1*0.98;
t:=t+n1;
inc(s);
until t>=n;
write(s);
end.
本人蒟蒻一枚，求指点（Pascal）
```
by _棉花糖_ @ 2017-11-28 20:05:48
等比数列？
by Kujolord @ 2017-11-28 20:55:43
```cpp
var c:longint;
a,n,b:real;
begin
read(a);
n:=2;
b:=n;
c:=1;
while n<a do begin//用while//
b:=b*0.98;
n:=n+b;
c:=c+1; end;
writeln(c);
end.
```
by Andysun06 @ 2017-12-15 22:01:08
//s:=1;//
加上
by Andysun06 @ 2017-12-15 22:02:18