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// Karol Kosinski 2025
#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a),_b=(b);i<_b;++i)
#define FR_(i,a,b) for(int i=(a),_b=(b);i<=_b;++i)
#define FD_(i,b,a) for(int i=(b),_a=(a);i>=_a;--i)
#define ALL(c) (c).begin(),(c).end()
#define SIZE(c) int((c).size())
#define X first
#define Y second
#define endl '\n'
#define NAM(x) #x,'=',x
using namespace std;
using LL = long long;
using ULL = unsigned long long;
using PII = pair<int, int>;
using TIII = tuple<int, int, int>;
template<class...T> void _cout(T...a){(cout<<...<<a);}

#ifndef ENABLE_DEBUG
#define DEB(k,p,f,x...)
#else
#define DEB(k,p,f,x...) {if(k)_cout("------",setw(4),__LINE__," : ",__FUNCTION__,endl);if(p)f(x);}
#endif
#define DEBF(f,x...)    DEB(1,1,f,x)
#define DEBL            DEBF(void,0)
#define DEBC(p,x...)    DEB(0,p,_cout,x)
#define DEBUG(x...)     DEBC(1,x)

constexpr int  MX = 1'005;
constexpr LL BIG = 1'000'000'000'001LL;

LL n, s;
int m;
pair<LL, LL> A[MX];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> m >> s;    
    FR_(i,1,m)
    {
        LL a, b;
        cin >> a >> b;
        A[i] = pair( a, b );
    }
    A[0] = pair( 0LL, 0LL );
    A[ m + 1 ] = pair( n + 1, n + 1 );
    m += 2;

    sort( A, A + m );
    int ind = -1;
    FOR(i,0,m)
    {
        if ( A[i].X <= s and s <= A[i].Y )
        {
            ind = i;
            break;
        }
    }
    LL L = BIG, R = BIG;
    FOR(i,ind+1,m)
    {
        if ( A[ i - 1 ].Y + 1 < A[i].X )
        {
            R = A[ i - 1 ].Y + 1;
            break;
        }
    }
    FD_(i,ind-1,0)
    {
        if ( A[i].Y + 1 < A[ i + 1 ].X )
        {
            L = A[ i + 1 ].X - 1;
            break;
        }
    }
    LL res = 0;
    if ( L == BIG ) res = R;
    else if ( R == BIG ) res = L;
    else if ( s - L <= R - s ) res = L;
    else res = R;
    cout << res << endl;
    return 0;
}