void fastscan(int &x)
{
    bool neg=false;
    register int c;
    x =0;
    c=getchar();
    if(c=='-')
    {
        neg = true;
        c=getchar();
    }
    for( ; (c>47 && c<58) ; c=getchar() )
        x = (x<<1) + (x<<3) +c -48;
    if(neg) x *=-1;
}