fast read

inline int read(){
    char ch;
	bool flag = false;
    int a = 0;
    while(!((((ch = getchar()) >= '0') && (ch <= '9')) || (ch == '-')));
    if(ch != '-'){
		a *= 10;
		a += ch - '0';
	}
	else flag = true;
    while(((ch = getchar()) >= '0') && (ch <= '9')){
		a *= 10;
		a += ch - '0';
	}
	if(flag) a = -a;
    return a;
}

void write(int a){
	if(a < 0){putchar('-');a = -a;}
    if(a >= 10) write(a/10);
    putchar(a % 10 + '0');
}