#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
set<int> a, b;
set<int> pre;
char str[10];
int main() {
  int n;
  cin >> n;
  long long ans = 1;
  a.insert(0);
  b.insert(1e9 + 5);
  for (int i = 0; i < n; ++i) {
    int x;
    scanf("%s%d", str, &x);
    if (str[1] == 'D') {
      int l = *a.rbegin();
      int r = *b.begin();
      if (x > l && x < r) {
        pre.insert(x);
      } else {
        if (x < l)
          a.insert(x);
        else
          b.insert(x);
      }
    } else {
      if (pre.count(x)) {
        ans *= 2;
        ans %= mod;
        for (auto it : pre) {
          if (it > x)
            b.insert(it);
          else if (it < x)
            a.insert(it);
        }
        pre.clear();
      } else {
        int l = *a.rbegin();
        int r = *b.begin();
        if (x == l) {
          a.erase(x);
          for (auto it : pre) {
            if (it != x) b.insert(it);
          }
        } else if (x == r) {
          b.erase(x);
          for (auto it : pre) {
            if (it != x) a.insert(it);
          }
        } else
          return puts("0");
        pre.clear();
      }
    }
  }
  int x = pre.size();
  ans *= (x + 1);
  ans %= mod;
  cout << ans << endl;
  return 0;
}
