【模板】快读
inline int read(){
int s=0,f=1;char ch=getchar();
while(!isdigit(ch)) {if(ch=='-') f=-1;ch=getchar();}
while(isdigit(ch)) s=s*10+ch-'0',ch=getchar();
return s*f;
}
inline int read(){
int s=0,f=1;char ch=getchar();
while(!isdigit(ch)) {if(ch=='-') f=-1;ch=getchar();}
while(isdigit(ch)) s=s*10+ch-'0',ch=getchar();
return s*f;
}