#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>

int main() {
    long long n, m, s;
    std::cin >> n >> m >> s;

    std::vector<std::pair<long long, long long>> intervals;

    for (int i = 0; i < m; i++) {
        long long l, r;
        std::cin >> l >> r;
        intervals.emplace_back(l, r);
    }

    std::sort(intervals.begin(), intervals.end());

    long long left = s - 1, right = s + 1;
    long long closest = LLONG_MAX;

    while (left >= 1) {
        bool occupied = false;
        for (auto &[l, r] : intervals) {
            if (left >= l && left <= r) {
                occupied = true;
                left = l - 1;
                break;
            }
        }
        if (!occupied) {
            closest = left;
            break;
        }
    }

    while (right <= n) {
        bool occupied = false;
        for (auto &[l, r] : intervals) {
            if (right >= l && right <= r) {
                occupied = true;
                right = r + 1;
                break;
            }
        }
        if (!occupied) {
            if (closest == LLONG_MAX || std::abs(s - right) < std::abs(s - closest)) {
                closest = right;
            }
            break;
        }
    }

    std::cout << closest << std::endl;
    return 0;
}