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#ifndef LOCAL
#pragma GCC optimize("O3")
#endif
#include <bits/stdc++.h>
#define FOR(i,p,k) for(int i=(p); i<=(k); ++i)
#define REP(i,k) FOR(i,0,(k)-1)
#define RFOR(i,p,n) for(int i=(p); i>=(n); --i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ssize(x) int((x).size())
#define fi first
#define se second
#define V vector
#define pb push_back
#define eb emplace_back
#define C const
#define pn printf("\n")
using namespace std;
typedef long long ll;
typedef V <int> vi;
typedef V <ll> vll;
typedef C int ci;
typedef C ll cll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
void chmin(auto &a, auto b){a=min(a,b);}
void chmax(auto &a, auto b){a=max(a,b);}
ci inf=2.1e9;
cll infll=4.5e18;
int I(){
    int z;
    scanf("%d", &z);
    //cin>>z;
    return z;
}
ll LL(){
    ll z;
    scanf("%lld", &z);
    //cin>>z;
    return z;
}
void ans(){
    cll n=LL(); ci m=I(); cll s=LL();
    V <pll> prz(m);
    bool czy=0;
    REP(i, m)
        prz[i].fi=LL(),prz[i].se=LL(),czy|=prz[i].fi<=s&&prz[i].se>=s;
    if (!czy){
        printf("%lld\n", s);
        return;
    }
    prz.eb(n+1, n+1);
    sort(all(prz));
    ll wp=-infll,wk=infll;
    ll ostzaj=0;
    for (C auto &[p,k] : prz){
        if (p!=ostzaj+1){
            if (p<=s)
                chmax(wp, p-1);
            if (p>=s)
                chmin(wk, ostzaj+1);
        }
        ostzaj=k;
    }
    cll w=abs(wp-s)<=abs(wk-s) ? wp : wk;
    printf("%lld\n", w);
}
int main(){
    //ios_base::sync_with_stdio(0),cin.tie(0);
    int tt=1;
    //tt=I();
    while (tt--)ans();
}