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#include <bits/stdc++.h>

#define rep(a,b,c) for(auto a = (b); a != (c); a++)
#define repD(a,b,c) for(auto a = (b); a != (c); a--)
#define repIn(a, b) for(auto& a : (b))
#define repIn2(a, b, c) for(auto& [a, b] : (c))

constexpr bool dbg = 1;
#define DEBUG if constexpr(dbg)
#define DC DEBUG std::cerr
#define eol std::endl

#define ll long long
#define pb push_back

using namespace std;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    ll n, m, s;
    cin >> n >> m >> s;
    vector<pair<ll, ll>> intervals(m);
    rep(i, 0ll, m) cin >> intervals[i].first >> intervals[i].second;
    ranges::sort(intervals);
    auto xd = ranges::upper_bound(intervals, pair{s, (ll)3e18}) - intervals.begin() - 1;
    //assert(intervals[xd].first <= s  &&  s <= intervals[xd].second);
    ll rightOne = xd;
    while(rightOne < m - 1 && intervals[rightOne].second + 1 == intervals[rightOne + 1].first) rightOne++;
    ll leftOne = xd;
    while(leftOne > 0 && intervals[leftOne - 1].second + 1 == intervals[leftOne].first) leftOne--;
    cout << ((intervals[rightOne].second == n || (intervals[leftOne].first > 1 && s - intervals[leftOne].first + 1 <= intervals[rightOne].second + 1 - s)) ? intervals[leftOne].first - 1 : intervals[rightOne].second + 1) << '\n';
}