077. Guess a number!.cpp

#include <iostream>
 
void minimize(int &a, int b) { a = std::min(a, b); }
void maximize(int &a, int b) { a = std::max(a, b); }
 
using namespace std;
 
int main() {
	int mx = 2 * 1000 * 1000 * 1000;
	int mn = -mx;
	
	int n; cin >> n;
	while (n --> 0) {
		string s; cin >> s;
		int x; cin >> x;
		string ans; cin >> ans;
		
		if (ans == "N") {
			if (s == ">=") s = "<";
			else if (s == "<") s = ">=";
			else if (s == "<=") s = ">";
			else s = "<=";
		}
		
		if (s == ">=") maximize(mn, x);
		else if (s == ">") maximize(mn, x + 1);
		else if (s == "<=") minimize(mx, x);
		else minimize(mx, x - 1);
	}
	
	if (mn <= mx) cout << mn;
	else cout << "Impossible";
}