#include <bits/stdc++.h>
#define int long long
using namespace std;
int n,x,y,k,m;
map<int, int> mp;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int getval(int pos){
    int ans = pos;
    for(auto [loc, val]: mp){
        if(loc <= pos){
            ans += val;
        }else{
            break;
        }
    }
    return ans;
}

signed main()
{
    fin >> n >> m >> k;
    for(int i = 1; i <= m; i++){
        fin >> x >> y;
        mp[x] += getval(y+1)-x;
    }
    fout << getval(k);
    return 0;
}