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# include <bits/stdc++.h>
typedef long long ll;
using namespace std;
# define For(i , l , r) for(int i = (l); i <= (r); i++)
# define Rep(i , n) For(i , 0 , (n) - 1)
# define size(x) (ll)x.size()
# define all(x) x.begin(),x.end()
# define MAXN 8002
const ll inf = 1e9 + 7;
const ll mod = 998244353;
ll n , m , k , ans = 0 , qq , t , timer = 0 , s;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m >> s;
    vector<pair<ll , ll> >seg(m);
    Rep (i , m) {
        cin >> seg[i].first >> seg[i].second;
    }
    sort(all(seg));
    set<pair<ll , ll> >st;
    Rep (i , size(seg)) {
        ll j = i;
        while (j + 1 < size(seg) && seg[j].second + 1 == seg[j + 1].first) {
              j++;
        }
        st.insert({seg[i].first , seg[j].second});
        i = j;
    }
    auto it = st.lower_bound({s + 1 , -inf});
    if (it == st.begin()) {
        cout << s;
        return 0;
    }
    it--;
    auto [l , r] = *it;
    if (abs(s - l) <= abs(s - r)) {
        if (l - 1 > 0) cout << l - 1;
        else cout << r + 1;
    }
    else if (r + 1 <= n) cout << r + 1;
    else cout << l - 1;

}
/*

*/