#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, a, b) for (register int i = a, end = b; i <= end; i++)
#define repd(i, a, b) for (register int i = a, end = b; i >= end; i--)
#define chkmax(a, b) a = max(a, b)
#define chkmin(a, b) a = min(a, b)
#define INF (1<<30)
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fst first
#define snd second
#define pii pair<int, int>
inline int read() {
int w = 0, f = 1; char c;
while (!isdigit(c = getchar())) f = c == '-' ? -1 : f;
while (isdigit(c)) w = (w << 3) + (w << 1) + (c ^ 48), c = getchar();
return w * f;
}
int N, M;
int main() {
return 0;
}