#include<stdio.h>

FILE *fin=fopen("stergeri.in","r"),
    *fout=fopen("stergeri.out","w");

int N,M,K;
int x[100005],y[100005];

int main(){
    fscanf(fin,"%d %d %d",&N,&M,&K);
    for(int i=1;i<=M;i++)
        fscanf(fin,"%d %d",&x[i],&y[i]);

    for(int i=M;i;i--)
        if(x[i]<=K)
            K+=y[i]-x[i]+1;
    fprintf(fout,"%d\n",K);
    fclose(fin);
    fclose(fout);
    return 0;
}