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#include <iostream>
#include <vector>
#include <list>
#include <tuple>
#include <queue>
#include <algorithm>

using namespace std;

typedef long long int lli;

struct range {
    lli beg;
    lli end;
    bool contais(lli x) {
        return x >= beg && x <= end;
    }
};


lli n, m, s;

bool comp(range a, range b) {
    return a.beg < b.beg;
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    vector<range> rang;
    cin >> n >> m >> s;

    lli cnt = m;
    while(cnt--) {
        range r;
        cin >> r.beg >> r.end;
        rang.push_back(r);
    }
    sort(rang.begin(), rang.end(), comp);

    vector<range> merged;
    range tmpr = rang[0];
    lli sRangIdx = -1;
    for ( int i = 1; i < m; ++i) {
        if (rang[i].beg - tmpr.end <= 1) {
            tmpr.end = rang[i].end;
        } else {
            merged.push_back(tmpr);
            if (tmpr.contais(s)) sRangIdx = merged.size() - 1;
            tmpr = rang[i];
        }
    }
    merged.push_back(tmpr);
    if (tmpr.contais(s)) sRangIdx = merged.size() - 1;

    lli rl, rr;
    rl = merged[sRangIdx].beg - 1;
    rr = merged[sRangIdx].end + 1;

    if (rl < 1) {
        cout << rr;
    } else if ( rr > n ) {
        cout << rl;
    } else {
        if ( s - rl <= rr - s ) {
            cout << rl;
        } else {
            cout << rr;
        }
    }
    cout << "\n";
}