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

typedef long long ll;
const ll INF = 1e18;
const int N = 2000;

pair <ll, ll> taken[N];
pair <ll, ll> Free[N];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    ll n, s;
    int m;
    cin >> n >> m >> s;

    for(int i = 0; i < m; i++) {
        ll b, e;
        cin >> b >> e;
        taken[i] = {b, e};
    }

    sort(taken, taken + m);
    
    int free_size = 0;

    for(int i = 0; i < m; i++) {
        if(i > 0 && taken[i - 1].second + 1 < taken[i].first)
            Free[free_size++] = {taken[i - 1].second + 1, taken[i].first - 1};
        else if(i == 0 && taken[i].first > 1)
            Free[free_size++] = {1, taken[i].first - 1};
    }

    if(taken[m - 1].second < n)
        Free[free_size++] = {taken[m - 1].second + 1, n};

    ll best = INF;
    for(int i = 0; i < free_size; i++) {
        if(abs(Free[i].first - s) < abs(best - s))
            best = Free[i].first;
        if(abs(Free[i].second - s) < abs(best - s))
            best = Free[i].second;
    }

    cout << best << "\n";
}