#include<fstream>
using namespace std;
int n, m, k, i, j;
struct capete{
    int a;
    int b;
};
capete x[100001];
int main(){
    ifstream f("stergeri.in");
    ofstream g("stergeri.out");
    f>>n>>m>>k;
    for(i=1; i<=m; i++)
        f>>x[i].a>>x[i].b;
    for(i=m; i>=1; i--)
        if(x[i].a<=k)
            k+=x[i].b-x[i].a+1;
    g<<k;
    return 0;
}