输入外挂

int read() {
    char ch;
    for (ch = getchar(); ch<'0' || ch>'9'; ch = getchar());
    int x = ch - '0';
    for (ch = getchar(); ch >= '0'&&ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
    return x;
}

 另一种更快的

inline char nc()
{
    static char buf[100000], *p1 = buf, *p2 = buf;
    return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 100000, stdin), p1 == p2) ? EOF : *p1++;
}
inline int _read() {
    char ch = nc(); int sum = 0;
    while (!(ch >= '0'&&ch <= '9'))ch = nc();
    while (ch >= '0'&&ch <= '9')sum = sum * 10 + ch - 48, ch = nc();
    return sum;
}