1 inline int read()   //快读
 2 {
 3     int x=0,f=1;
 4     char ch=getchar();
 5     while (ch<'0' || ch>'9')
 6     {
 7         if (ch=='-') f=-1;
 8         ch=getchar();
 9     }
10     while (ch>='0' && ch<='9') x=x*10+ch-'0',ch=getchar();
11     return x*f;
12 }
13 
14 inline void write(int x)   //快写
15 {
16      if (x<0) putchar('-'),x=-x;
17      if (x>9) write(x/10);   //注意是大于9不是大于10
18      putchar(x%10+'0');
19 }