超級快讀

namespace fastIO {
#define BUF_SIZE 100000
    bool IOerror = 0;
    inline char nc() {
        static char buf[BUF_SIZE], * p1 = buf + BUF_SIZE, * pend = buf + BUF_SIZE;
        if (p1 == pend) {
            p1 = buf;
            pend = buf + fread(buf, 1, BUF_SIZE, stdin);
            if (pend == p1) {
                IOerror = 1;
                return -1;
            }
        }
        return *p1++;
    }
    inline bool blank(char ch) {
        return ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t';
    }
    inline void Read(int& x) {
        char ch;
        while (blank(ch = nc()));
        if (IOerror) return;
        for (x = ch - '0';(ch = nc()) >= '0' && ch <= '9';x = x * 10 + ch - '0');
    }
    inline void Read(long long int& x) {
        char ch;
        while (blank(ch = nc()));
        if (IOerror) return;
        for (x = ch - '0';(ch = nc()) >= '0' && ch <= '9';x = x * 10 + ch - '0');
    }
#undef BUF_SIZE
};