# include <stdio.h>
long long int a[100010],b[100010],n,m,k,i,ok;
int main ()
{
freopen ("stergeri.in","r",stdin);
freopen ("stergeri.out","w",stdout);
scanf ("%lli",&n);
scanf ("%lli",&m);
scanf ("%lli",&k);
for (i=1;i<=m;i++)
scanf ("%lli%lli",&a[i],&b[i]);
ok=0;
while (ok==0)
{
ok=1;
for (i=1;i<=m;i++)
if (a[i]!=-10)
if (k>=a[i])
{
k=k+(b[i]-a[i]+1);
a[i]=-10;
ok=0;
}
}
printf ("%lli",k);
return 0;
}