#include <iostream>
#include <algorithm>

struct range
{
    int64_t v;
    int t;

    bool operator<(const range &b) const
    {
        if (v == b.v) return t > b.t;
        return v < b.v;
    }
};

const int MAX = 1000 + 2;

int64_t n, m, s, l, r, p ,d;
range R[4 * MAX];

int main()
{
    std::ios_base::sync_with_stdio(0);
    std::cin >> n >> m >> s;

    for (int i = 0; i < m; ++i)
    {
        std::cin >> l >> r;
        R[4 * i] = {l, +1};
        R[4 * i + 1] = {r, -1};
        R[4 * i + 2] = {l-1, 0};
        R[4 * i + 3] = {r+1, 0};
    }
    std::sort(R, R + m * 4);
    int x = 0;

    for (int i=0;i<m*4;++i) {
        x += R[i].t;
        if (R[i].v >= 1 && R[i].v <= n && x == 0 && R[i].t == 0) {
            if (p == 0 || std::abs(s-R[i].v) < d) {
                d = std::abs(s-R[i].v);
                p = R[i].v;
            }
        }
    }
    std::cout << p << std::endl;
    return 0;
}