#include <bits/stdc++.h>

using namespace std;

int A[200000], B[200000];

int main() {
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);

    int n, m, k;
    cin>>n>>m>>k;

    for(int i=1; i<=m; i++)
        cin>>A[i]>>B[i];

    for(int i=m; i; i--) {
        if(A[i] <= k)
            k += B[i] - A[i] + 1;
    }

    cout << k;

    return 0;
}