func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 2e5 + 6;   const int maxlog = 20;   const long long inf = 1e18;   const int mod = 1e9 + 7;   const long long base = 307;   map<long long, int> cnt1, cnt2;   set<int> st;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n;     cin >> n;     int need = (n + 1) / 2;     for (int i = 0; i < n; i++) {       int x, y;       cin >> x >> y;       cnt1[x]++;       if (y != x) cnt2[y]++;       st.insert(x);       st.insert(y);     }     int ans = mod;     for (set<int>::iterator it = st.begin(); it != st.end(); it++) {       int x = *it;       int kol = cnt1[x] + cnt2[x];       if (kol < need) continue;       int new_need = need - cnt1[x];       ans = min(ans, new_need);     }     if (ans == mod)       cout << -1;     else       cout << max(0, ans);     return 0;   }   