#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}
int64_t rs64() {
	int64_t n;
	scanf("%" SCNd64, &n);
	return n;
}
int main() {
	int n = ri(), k = ri();
	if (k > n) {
		puts("-1");
		return 0;
	}
	std::vector<int> hen[n];
	for (int i = 0; i + 1 < n; i++) {
		int a = ri() - 1;
		int b = ri() - 1;
		hen[a].push_back(b);
		hen[b].push_back(a);
	}
	std::vector<int> depth(n, -1);
	depth[0] = 0;
	std::queue<int> que;
	que.push(0);
	while (que.size()) {
		int i = que.front();
		que.pop();
		for (auto j : hen[i]) {
			if (depth[j] == -1) {
				depth[j] = depth[i] + 1;
				que.push(j);
			}
		}
	}
	std::sort(depth.begin(), depth.end());
	int64_t res = 0;
	for (int i = 0; i < k; i++) res += depth[i];
	printf("%" PRId64 "\n", res);
	return 0;
}