#include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     long long int max = 2000000001, min = -2000000001;     long long int x, y;     string question;     char answer;     int i;     for (i = 0; i < n; i++) {       int tmp;       cin >> question;       cin >> x >> answer;       cin.get();       if (question[0] ==  < ) {         if (answer ==  Y ) {           if (x <= max)             if (question.size() == 2)               max = x;             else               max = x - 1;         } else {           if (x >= min)             if (question.size() == 2)               min = x + 1;             else               min = x;         }       } else {         if (question[0] ==  > ) {           if (answer ==  Y ) {             if (x >= min)               if (question.size() == 2)                 min = x;               else                 min = x + 1;           } else {             if (x <= max)               if (question.size() == 2)                 max = x - 1;               else                 max = x;           }         }       }     }     if (min > max) {       cout <<  Impossible  << endl;       return 0;     } else {       if (max == min)         cout << min << endl;       else         cout << min + 1 << endl;     }     return 0;   }   