Language: C++

#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define int long long
#define rep(i, n) for (int i = 0; i < n; i++)

#define n_l '\n'
template <typename T, size_t N> int SIZE(const T (&t)[N]) { return N; } template<typename T> int SIZE(const T &t) { return t.size(); } string to_string(const string s, int x1 = 0, int x2 = 1e9) { return '"' + ((x1 < s.size()) ? s.substr(x1, x2 - x1 + 1) : "") + '"'; } string to_string(const char* s) { return to_string((string) s); } string to_string(const bool b) { return (b ? "true" : "false"); } string to_string(const char c) { return string({c}); } template<size_t N> string to_string(const bitset<N> &b, int x1 = 0, int x2 = 1e9) { string t = ""; for (int __iii__ = min(x1, SIZE(b)),  __jjj__ = min(x2, SIZE(b) - 1); __iii__ <= __jjj__; ++__iii__) { t += b[__iii__] + '0'; } return '"' + t + '"'; } template <typename A, typename... C> string to_string(const A (&v), int x1 = 0, int x2 = 1e9, C... coords); int l_v_l_v_l = 0, t_a_b_s = 0; template <typename A, typename B> string to_string(const pair<A, B> &p) { l_v_l_v_l++; string res = "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; l_v_l_v_l--; return res; } template <typename A, typename... C> string to_string(const A (&v), int x1, int x2, C... coords) { int rnk = rank<A>::value; string tab(t_a_b_s, ' '); string res = ""; bool first = true; if (l_v_l_v_l == 0) res += n_l; res += tab + "["; x1 = min(x1, SIZE(v)), x2 = min(x2, SIZE(v)); auto l = begin(v); advance(l, x1); auto r = l; advance(r, (x2 - x1) + (x2 < SIZE(v))); for (auto e = l; e != r; e = next(e)) { if (!first) { res += ", "; } first = false; l_v_l_v_l++; if (e != l) { if (rnk > 1) { res += n_l; t_a_b_s = l_v_l_v_l; }; } else { t_a_b_s = 0; } res += to_string(*e, coords...); l_v_l_v_l--; } res += "]"; if (l_v_l_v_l == 0) res += n_l; return res; } void dbgm() {;} template<typename Heads, typename... Tails> void dbgm(Heads H, Tails... T) { cout << to_string(H) << " | "; dbgm(T...); }
#define dbg(...) cout << "[" << #__VA_ARGS__ << "]: "; dbgm(__VA_ARGS__); cout << endl

bool comp(pair <int, int> x, pair <int, int> y) {
   if (x.ss > y.ss)
      return true;
   else
      return false;
}

int32_t main() {
   ios::sync_with_stdio(false);   cin.tie(NULL);   cout.tie(NULL);

   int n;
   cin >> n;
   vector <pair <int, int>> v(n);
   for (auto &i : v)
      cin >> i.ff >> i.ss;
   if (n % 2) {
      sort(v.begin(), v.end());
      int lo = v[n / 2].ff;
      sort(v.begin(), v.end(), comp);
      int hi = v[n / 2].ss;
      cout << max(hi - lo + 1, 0ll) << endl;
   } else {
      sort(v.begin(), v.end());
      int lo1 = v[n / 2].ff;
      int lo2 = v[(n - 1) / 2].ff;
      sort(v.begin(), v.end(), comp);
      int hi1 = v[n / 2].ss;
      int hi2 = v[(n - 1) / 2].ss;
      cout << max({(hi1 - lo1 + 1), (hi2 - lo2 + 1) 0ll}) << endl;
   }

   return 0;
}

Compiler output:
a.cc: In function 'int32_t main()':
a.cc:40:53: error: expected '}' before numeric constant
   40 |       cout << max({(hi1 - lo1 + 1), (hi2 - lo2 + 1) 0ll}) << endl;
      |                   ~                                 ^~~
a.cc:40:52: error: expected ')' before numeric constant
   40 |       cout << max({(hi1 - lo1 + 1), (hi2 - lo2 + 1) 0ll}) << endl;
      |                  ~                                 ^~~~
      |                                                    )
a.cc:40:57: error: expected primary-expression before ')' token
   40 |       cout << max({(hi1 - lo1 + 1), (hi2 - lo2 + 1) 0ll}) << endl;
      |                                                         ^
a.cc: At global scope:
a.cc:43:4: error: expected unqualified-id before 'return'
   43 |    return 0;
      |    ^~~~~~
a.cc:44:1: error: expected declaration before '}' token
   44 | }
      | ^