#include <bits/stdc++.h>
using namespace std;
template <class T>
inline void input(T &x) {
  register char c = getchar();
  x = 0;
  int neg = 0;
  for (; ((c < 48 || c > 57) && c != '-'); c = getchar())
    ;
  if (c == '-') {
    neg = 1;
    c = getchar();
  }
  for (; c > 47 && c < 58; c = getchar()) {
    x = (x << 1) + (x << 3) + c - 48;
  }
  if (neg) x = -x;
}
inline long long bigmod(long long p, long long e, long long M) {
  long long ret = 1;
  for (; e > 0; e >>= 1) {
    if (e & 1) ret = (ret * p) % M;
    p = (p * p) % M;
  }
  return ret;
}
template <class T>
inline T gcd(T a, T b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <class T>
inline T modinverse(T a, T M) {
  return bigmod(a, M - 2, M);
}
const int N = 3e6 + 6;
char s[N], ans[N];
int l[5005], r[5005];
int n, k;
int T[5 * N];
int first[N];
void build(int n, int b, int e) {
  if (b == e) {
    T[n] = 1;
    return;
  }
  int mid = (b + e) / 2;
  build(((n) << 1), b, mid);
  build(((n) << 1 | 1), mid + 1, e);
  T[n] = T[((n) << 1)] + T[((n) << 1 | 1)];
}
void update(int n, int b, int e, int pos, int v) {
  if (b == e && b == pos) {
    T[n] = 0;
    return;
  }
  int mid = (b + e) / 2;
  if (pos <= mid)
    update(((n) << 1), b, mid, pos, v);
  else
    update(((n) << 1 | 1), mid + 1, e, pos, v);
  T[n] = T[((n) << 1)] + T[((n) << 1 | 1)];
}
int get(int n, int b, int e, int k) {
  if (b == e) return b;
  int mid = (b + e) / 2;
  if (T[((n) << 1)] >= k)
    return get(((n) << 1), b, mid, k);
  else
    return get(((n) << 1 | 1), mid + 1, e, k - T[((n) << 1)]);
}
int main() {
  scanf("%s%d%d", s, &k, &n);
  for (int i = 0; i < n; i++) input(l[i]), input(r[i]);
  build(1, 1, k);
  int now = k;
  for (int i = n - 1; i >= 0; i--) {
    for (int j = 1, t = l[i] + 1; j <= r[i] - l[i] + 1 && r[i] < T[1]; j++) {
      if (t > r[i]) t = l[i];
      int p = get(1, 1, k, r[i] + 1);
      update(1, 1, k, p, -1);
      first[p] = get(1, 1, k, t);
      t += 2;
    }
  }
  int cnt = 0;
  for (int i = 1; i <= k; i++) {
    if (first[i] > 0)
      ans[i] = ans[first[i]];
    else
      ans[i] = s[cnt++];
  }
  cout << (ans + 1) << endl;
  return 0;
}
