#include <cstdio>
#include <iostream>
#define MMAX 100001

using namespace std;

pair <int,int> v[MMAX];

int main(){
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    int n,m,i,k;
    scanf("%d%d%d",&n,&m,&k);
    for (i=0;i<m;i++)
        scanf("%d%d",&v[i].first,&v[i].second);
    for (i=m-1;i>-1;i--)
        if (v[i].first <= k)
            k += v[i].second - v[i].first + 1;
    printf("%d",k);
    return 0;
}