#include <iostream>
#include <fstream>
using namespace std;
int Load, Queries, Potassium;
int QR1[100001];
int QR2[100001];
/*void Corupe(char *FN){
    char c;
    int a = 0, b = 0;
    bool FRT = true;
    bool DBG = true;
    ifstream myFile(FN, ios::ate);
    streampos size = myFile.tellg();
    for(int i = 1; i <= size; i++){
        myFile.seekg(-i, ios::end);
        myFile.get(c);
        if (c >= '0' && c <= '9') {
            if (FRT) a = a*10 + (c - 48);
            else b = b * 10 + (c - 48);
        }

        if (c == ' ') {
            FRT = !FRT;
        }

        if (c == '\n') {
            if (DBG == false) {
                FRT = !FRT;
                if (a <= Potassium && (a != 0 || b != 0))
                    Potassium += b - a + 1;

                a = 0;
                b = 0;
                DBG = true;
            } else
                DBG = false;
        }
    }
}

int main() {
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);
    cin >> Load >> Queries >> Potassium;
    Corupe("stergeri.in");
    cout << Potassium;
}*/

int main() {
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);
    cin >> Load >> Queries >> Potassium;

    for (int i = 0; i < Queries; i++)
        cin >> QR1[i] >> QR2[i];

    for (int i = Queries - 1; i >= 0; i--) {
        if (QR1[i] <= Potassium) {
            Potassium += QR2[i] - QR1[i] + 1;
        }
    }

    cout << Potassium;
}