快读
inline long read(){
long x=0,t=1;
char ch=getchar();
while(ch<'0' || ch>'9'){
if(ch='-') t=-1;
ch=getchar();
}
while(ch>='0' && ch<='9'){
x=(x<<1)+(x<<3)+(ch^48);
ch=getchar();
}
return x*t;
}
快写
inline void write(long x){ if(x<0) { x=-x; putchar('-'); } if(x>0){ write(x/10); putchar(x%10+'0'); } }