FastIO 模板
#define gc getchar
#define pc putchar
inline int read(){
int x=0;char c=gc();bool f=0;
while(!isdigit(c)){if(c=='-')f=1;c=gc();}
while(isdigit(c)){x=(x<<3)+(x<<1)+c-48;c=gc();}
if(f)x=-x;
return x;
}
inline void write(int x){
if(x<0){pc('-');x=-x;}
if(x>9)write(x/10);
pc(x%10+'0');
}