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#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define st first
#define nd second
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;

#ifdef LOCAL
#define DTP(x, y)                                    \
    auto operator<<(auto &o, auto a)->decltype(y, o) \
    {                                                \
        o << "(";                                    \
        x;                                           \
        return o << ")";                             \
    }
DTP(o << a.first << ", " << a.second, a.second);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { ((cerr << x << ", "), ...) << '\n'; }
#define debug(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define debug(...) 42
#endif

void solve()
{
    ll n, m, s;
    cin >> n >> m >> s;
    vector<pll> V(m);
    for (auto &[a, b] : V)
        cin >> a >> b;
    sort(all(V));
    vector<pll> T{V[0]};
    for (int i = 1; i < m; i++)
        if (T.back().second + 1 == V[i].first)
            T.back().second = V[i].second;
        else
            T.push_back(V[i]);
    debug(T);
    pll ANS;
    for (auto &[a, b] : T)
        if (a <= s && s <= b)
            ANS = {a, b};
    if (ANS.second == n)
        ANS.second = 3 * n;
    if (ANS.first == 1)
        ANS.first = -3 * n;
    debug(ANS);
    if (ANS.second - s < s - ANS.first)
        cout << ANS.second + 1 << endl;
    else
        cout << ANS.first - 1 << endl;
}

main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    int Z = 1;
    // cin >> Z;
    while (Z--)
        solve();
}