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#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) X.begin(), X.end()
#define sz(X) int(size(X))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
using pii = pair<int, int>; using vi = vector<int>;
using ll = long long; using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) { *(int *)0 = 0; });
#define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; }
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { (( cerr << x << ", " ), ...) <<
'\n'; }
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define deb(...) 0
#endif
 

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n, m, s; cin >> n >> m >> s;
    vector<pair<ll, ll>> v(m);
    rep(i, m){
        cin >> v[i].st >> v[i].nd;
    }
    sort(all(v));
    ll res = -1;
    ll dist = 1e18;
    ll pos = 1;
    rep(i, m){
        if(pos < v[i].st){
            ll a = pos;
            ll b = v[i].st - 1;
            if(a <= s && s <= b){
                res = s;
                dist = 0;
            }
            ll d = abs(a - s);
            if(d < dist){
                dist = d;
                res = a;
            }
            d = abs(b - s);
            if(d < dist){
                dist = d;
                res = b;
            }
        }
        pos = v[i].nd + 1;
    }
    if(pos <= n){
        ll a = pos;
        ll b = n;
        if(a <= s && s <= b){
            res = s;
            dist = 0;
        }
        ll d = abs(a - s);
        if(d < dist){
            dist = d;
            res = a;
        }
        d = abs(b - s);
        if(d < dist){
            dist = d;
            res = b;
        }
    }
    cout << res << "\n";
    return 0;
}