//UVA1218PerfectService
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const int MAXN = 1e4 + 10;
const int INF = 1e9;
vector<int> G[MAXN], vertices;
int d[MAXN][3], p[MAXN];
void dfs(int now, int father) {
p[now] = father;
vertices.push_back(now);
for(int i = 0; i < G[now].size(); i++) {
int v = G[now][i];
if(father == v) continue;
dfs(v, now);
}
}//定好dp遍历时的顺序
int main() {
int N;
while(scanf("%d", &N) == 1 && N != -1) {
int a, b;
vertices.clear();
for(int i = 0; i <= N; i++) G[i].clear();
for(int i = 0; i < N - 1; i++) {
scanf("%d%d", &a, &b);
a--; b--;
G[a].push_back(b);
G[b].push_back(a);
}//建图
dfs(0, -1);//建立之后动态规划的遍历顺序
for(int k = vertices.size() - 1; k >= 0; k--) {
int u = vertices[k];
//
d[u][0] = 1; d[u][1] = 0;
//若k是服务器，则将d[k]初始化为1，否则初始化为0
for(int i = 0; i < G[u].size(); i++) {
//printf("u = %d\n", vertices[k]);
int v = G[u][i];
if(v == p[u]) continue; //遇到父节点则跳过
d[u][0] += min(d[v][0], d[v][1]);
//printf("d[u][0] = %d, d[u][1] = %d\n", d[u][0], d[u][1]);
d[u][1] += d[v][2];
if(d[u][0] > INF) d[u][0] = INF;
if(d[u][1] > INF) d[u][1] = INF;
}
d[u][2] = INF;
for(int i = 0; i < G[u].size(); i++) {
int v = G[u][i];
if(v == p[u]) continue;
d[u][2] = min(d[u][1] - d[v][2] + d[v][0], d[u][2]);
//printf("d[u][2] = %d\n", d[u][2]);
}
}
printf("%d\n", min(d[0][0], d[0][2]));
int flag;
scanf("%d", &flag);
if(flag == -1) break;
}
return 0;
}
/*
6
1 3
2 3
3 4
4 5
4 6
0
2
1 2
-1
*/
