#include <cstdio>
#include <stack>

using namespace std;

stack<int> op_store;

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

    int k, x, y, n, m;

    scanf("%d %d %d", &n, &m, &k);

    for(int i=1; i<=m; i++)
    {
        scanf("%d %d", &x, &y);
        op_store.push(x);
        op_store.push(y);
    }

    while(op_store.size()!=0)
    {
        y=op_store.top();
        op_store.pop();
        x=op_store.top();
        op_store.pop();
        if(x <= k)
        {
            k+= y - x + 1;
        }
    }

    printf("%d",k);
}