#include <stdio.h>
int x[100000],y[100000];
int main(){
    FILE *fin=fopen("stergeri.in","r");
    FILE *fout=fopen("stergeri.out","w");
    int n,m,k,i;

    fscanf(fin,"%d%d%d",&n,&m,&k);
    for(i=0; i<m; i++)
        fscanf(fin,"%d%d",&x[i],&y[i]);
    for(i=m-1; i>=0; i--)
        if(x[i]<=k)
            k+=y[i]-x[i]+1;
    fprintf(fout,"%d",k);
    fclose(fin);
    fclose(fout);
    return 0;
}