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#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "(" << p.first << ", " << p.second <<")";
}
auto operator<<(auto &o, auto x)-> decltype(x.end(), o) {
    o << "{";int i = 0;
    for(auto e : x) o << ", "+!i++<<e;
    return o <<"}";
}
#define debug(x...) cerr << "["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define pb push_back
#define fi first
#define se second
typedef pair <int, int> pii;


void test() {
    debug("TC______________________");
    int n, m, s; cin>>n>>m>>s;
    vector <pii> intervals(m);

    for (int i=0; i<m; ++i) {
        cin>>intervals[i].fi>>intervals[i].se;
    }
    sort(all(intervals));
    int res = 1e16+1;
    int lst = 1;
    int ret = 1;
    for (auto &[x, y] : intervals) {
        int k = x - 1;
        debug(x, y, lst, k);
        if (lst > k) {
            lst = y+1;
            continue; 
        }
        debug(lst, k);
        int o1 = abs(s-lst);
        int o2 = abs(s-k);
        if (o1 < res) {
            res = o1;
            ret = lst;
        }
        if (o2 < res) {
            res = o2;
            ret = k;
        }
        lst = y+1;
    }

    if (lst <= n) {
        int o3 = abs(lst - s);
        if (o3 < res) {
            ret = lst;
        }
    }
    cout<<ret<<'\n';
}

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  int t = 1; 
  while (t--) {
    test();
  }
}