快讀

inline int read(){
    int x=0;
    char c=getchar();
    bool flag=0;
    while(c<'0'||c>'9'){
        if(c=='-')
            flag=1;
        c=getchar();
    }
    while(c>='0'&&c<='9'){
        x=(x<<3)+(x<<1)+c-'0';
        c=getchar();
    }
    if(flag)
        x=-x;
    return x;
}