快读输入

inline int read()
{
    char ch=getchar();
	int x=0,f=1;
    while(ch<'0'||ch>'9') {if(ch=='-')f=-1,ch=getchar();}
    while(ch>='0'&&ch<='9') {x=(x<<3)+(x<<1)+(ch^48),ch=getchar();}
    return x*f;
}