快读快写模版
long long read(){
char c = getchar();
long long x = 0, f = 1;
for (; c < '0' || c > '9'; c = getchar())
if (c == '-') f = -1;
for (; c >= '0' && c <= '9'; c = getchar())
x = (x << 1) + (x << 3) + (c ^ 48);
return x * f;
}
void print(long long x){
if (x < 0) x = -x, putchar('-');
if (x > 9) print(x / 10);
putchar(x % 10 + '0');
}
