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#include <bits/stdc++.h>


using namespace std;

const int M = 1003;
pair<long long, long long> tab[M];

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

    long long n, m, s;
    cin >> n >> m >> s;

    for(int i = 0; i < m; i++) {
        cin >> tab[i].first >> tab[i].second;
    }

    sort(tab, tab + m);

    int a = 0, b = m;
    int mid;
    while(a < b) {
        mid = (a + b) / 2;
        
        if(s < tab[mid].first) {
            b = mid;
        }
        else if(tab[mid].second < s) {
            a = mid + 1;
        }
        else break;
    }

    int i = mid;
    while(i > 0  &&  tab[i-1].second == tab[i].first - 1) i--;
    long long left_free = tab[i].first - 1;

    i = mid;
    while(i < m-1  &&  tab[i].second + 1 == tab[i+1].first) i++;
    long long right_free = tab[i].second + 1;

    if(left_free == 0) cout << right_free << "\n";
    else if(right_free == n+1) cout << left_free << "\n";
    else {
        if(s - left_free > right_free - s) cout << right_free << "\n";
        else cout << left_free << "\n";
    }


    return 0;
}