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//Krzysztof Pieprzak
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int,int> pii;
typedef pair<long long, long long> pll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

#define Size(x) (int)x.size()
#define VAR(v,n) auto v = (n)
#define FOR(i,a,b) for(VAR(i,a); i < (b); ++i)
#define FORE(i,a,b) for(VAR(i,a); i <= (b); ++i)
#define FORREV(i,a,b) for(VAR(i,b); i >= (a); --i)
#define FORSTEP(i,a,b,step) for(VAR(i,a); i < (b); i += (step))
#define FOREACH(i,c) for(auto i : (c))
#define FOREACHS(i,c,n) for(VAR(i,&(c)[0]); i-(c)<(n); ++i)
#define ALL(x) x.begin(),x.end()
#define CLEAR(t) memset(t, 0, sizeof(t))
#define F first
#define S second
#define MP make_pair
#define PUB push_back
#define POB pop_back
#define pieprzu ios_base::sync_with_stdio(0);
#define debug_enabled true
#define debug(name) if(debug_enabled) cout << endl << name << endl; if(debug_enabled)

const int    INF = 1000000001;
const double EPS = 10e-9;

const int MAXM = 1000;

pll t[MAXM + 5];

ll robrob() {
    ll n, s;
    int m;
    scanf("%lld %d %lld", &n, &m, &s);

    ll a, b;
    FOR (i, 0, m) {
        scanf("%lld %lld", &a, &b);
        t[i] = MP(a, b);
    }

    sort(t, t + m);

    ll mxFree = 0;
    ll lastTaken = 0;
    ll candidate1 = 0;
    ll candidate2 = n + 1;
    int i = 0;
    for (; i < m && !(t[i].F > s && t[i].F > lastTaken + 1); ++i) {
        if (t[i].F > lastTaken + 1) {
            mxFree = t[i].F - 1;
        }

        if (t[i].F <= s && t[i].S >= s) {
            candidate1 = mxFree;
        }

        lastTaken = t[i].S;
    }

    candidate2 = t[i - 1].S + 1;

    if (candidate1 != 0 && candidate2 != n + 1) {
        return s - candidate1 <= candidate2 - s ? candidate1 : candidate2;
    } else {
        return candidate1 == 0 ? candidate2 : candidate1;
    }
}

void rob(int test) {
    printf("%lld\n", robrob());
}

int main() {
    int test = 1;
    //scanf("%d", &test);

    FORE (i, 1, test) rob(i);

    return 0;
}