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#include<bits/stdc++.h>

#define llong long long
#define ldouble long double
#define uint unsigned int
#define ulong unsigned long long

using namespace std;

void solve() {
    llong n, s;
    int m;
    cin >> n >> m >> s;

    vector<llong> l(m), r(m);
    bool s_in = false;
    for (int i = 0; i < m; i++) {
        cin >> l[i] >> r[i];
        if (l[i] <= s && s <= r[i]) s_in = true;
    }
    if (!s_in) {
        l.push_back(s); r.push_back(s);
    }

    vector<int> perm(m);
    if (!s_in) perm.push_back(m);
    iota(perm.begin(), perm.end(), 0);
    sort(perm.begin(), perm.end(), [&](int i, int j) {
        return r[i] < r[j];
    });

    vector<llong> lp, rp;

    llong lc = l[perm[0]], rc = r[perm[0]];
    for (int i : perm) {
        if (l[i] > rc + 1) {
            lp.push_back(lc);
            rp.push_back(rc);
            lc = l[i];
            rc = r[i];
        } 
        else rc = r[i];
    }
    lp.push_back(lc);
    rp.push_back(rc);

    llong ans;

    for (int i = 0; i < lp.size(); i++) {
        if (lp[i] <= s && s <= rp[i]) {
            if (lp[i] == 1) ans = rp[i] + 1;
            else if (rp[i] == n) ans = lp[i] - 1;
            else ans = s - lp[i] <= rp[i] - s ? lp[i] - 1 : rp[i] + 1;
            break;
        }
    }

    cout << ans << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    solve();

    return 0;
}