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#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define MOD 1000000009
#define INF 1000000019
#define INFL 1000000000000000099LL

ll n,m,s,a,b;
vector<pair<ll,ll>>v1,v2;
int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    cin>>m>>n>>s;
    for(ll i=0;i<n;i++){
        cin>>a>>b;
        v1.pb({a,b});
    }
    sort(v1.begin(),v1.end());
    v2.pb(v1[0]);
    for(ll i=1;i<n;i++){
        if(v1[i].ff-1==v2.back().ss){
            v2.back().ss=v1[i].ss;
        }
        else{
            if(v2.back().ff<=s && s<=v2.back().ss){
                if(v2.back().ss<m && (v2.back().ss-s<s-v2.back().ff || v2.back().ff-1<1))
                    cout<<v2.back().ss+1;
                else
                    cout<<v2.back().ff-1;
                return 0;
            }
            v2.pb(v1[i]);
        }
    }
    if(v2.back().ss<m && (v2.back().ss-s<s-v2.back().ff || v2.back().ff-1<1))
        cout<<v2.back().ss+1;
    else
        cout<<v2.back().ff-1;
    return 0;
}