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#include<bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
    cin.tie(0)->sync_with_stdio(0);
    ll n, m, l, r, s;
    cin >> n >> m >> s;l=r=s;
    vector<array<ll, 2>> segs(m);
    for(auto &[l, r] : segs) cin >> l >> r;
    
    for(bool cont = true; cont;) {
        cont = false;
        for(auto [a, b] : segs) {
            if(a <= l && l <= b) l = a - 1, cont = true;
            if(a <= r && r <= b) r = b + 1, cont = true;
        }
    }
    ll ans = 1ll<<50;
    if(l >= 1 && l <= n && abs(ans-s) > abs(l-s)) ans = l;
    if(r >= 1 && r <= n && abs(ans-s) > abs(r-s)) ans = r;
    cout << ans << '\n';
}