#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long upper_limit = 1e9;
  long long lower_limit = -1e9;
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int c, d;
    cin >> c >> d;
    if (d == 2) {
      upper_limit = min(upper_limit, 1899LL);
    } else {
      lower_limit = max(lower_limit, 1900LL);
    }
    lower_limit += c;
    upper_limit += c;
  }
  if (upper_limit < lower_limit) {
    cout << "Impossible";
  } else if (upper_limit > 1e8) {
    cout << "Infinity";
  } else {
    cout << upper_limit;
  }
}
