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#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdint>

int main() {
    uint64_t n;
    int m;
    uint64_t s;

    std::cin >> n >> m >> s;

    std::vector<std::pair<uint64_t, uint64_t>> intervals(m, {0, 0});
    for (int i = 0; i < m; ++i) {
        uint64_t l;
        uint64_t r;

        std::cin >> l >> r;
        intervals[i] = std::make_pair(l, r);
    }

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

    uint64_t position = 0;
    auto [l, r] = intervals[0];
    for (int i = 1; i < m; ++i) {
        auto [l1, r1] = intervals[i];
        if (l1 != r + 1) {
            if (l <= s && s <= r) {
                uint64_t distance = n + 1;
                if (l != 1) {
                    position = l - 1;
                    distance = s - (l - 1);
                }
                if (r != n && distance > r + 1 - s) {
                    position = r + 1;
                }
                break;
            }
            l = l1;
        }
        r = r1;
    }

    if (l <= s && s <= r) {
        uint64_t distance = n + 1;
        if (l != 1) {
            position = l - 1;
            distance = s - (l - 1);
        }
        if (r != n && distance > r + 1 - s) {
            position = r + 1;
        }
    }

    std::cout << position << std::endl;

    return 0;
}