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#include <bits/stdc++.h>
#define INF (long long int)(1e15)
using namespace std;

struct seg {
    long long int from;
    long long int to;
    void set(long long int a, long long int b) {
        from = a;
        to = b;
    }
};

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

    long long int n, m, s;            //houses, segments, school
    cin >> n >> m >> s;
    vector<seg> segments(m+2);
    segments[0].set(-INF, 0);
    segments[m+1].set(n+1, INF);
    for(int i=1; i<=m; i++) {
        long long int a, b;
        cin >> a >> b;
        segments[i].set(a, b);
    }
    sort(segments.begin(), segments.end(), [](seg &a, seg &b) {return a.to < b.to;});

    int school;         //segment that contains the school
    for(int i=0; i<m+2; i++) {            //brute
        if(segments[i].from <= s && s <= segments[i].to) {
            school = i;
            break;
        }
    }

    int left = school;
    while(left > 0 && segments[left].from == segments[left-1].to+1) {
        left--;
    }
    int right = school;
    while(right < m+1 && segments[right].to == segments[right+1].from-1) {
        right++;
    }

    long long int a = segments[left].from-1;            // a<b
    long long int b = segments[right].to+1;
    if(s-a > b-s) {
        cout << b;
    }
    else {
        cout << a;
    }

    return 0;
}