勿喷QAQ

#include <bits/stdc++.h>
using namespace std;

int main() {
	long long a, b, c;
	cin >> a >> b >> c;
	if (c == a + b && c == a - b) {
		cout << "?";
	} else if (c == a + b && c != a - b) {
		cout << "+";
	} else if (c != a + b && c == a - b) {
		cout << "-";
	} else {
		cout << "!";
	}
	return 0;
}