'''
Given three integers a, b, and c, return + if the equation a + b = c is true, and - if the equation a - b = c is true

Example 1
Input:
a = 1; b = 2; c = 3
Output:
+
Example 2
Input:
a = 2; b = 9; c = -7
Output:
-
'''

class Solution(object):
    def solve(self, a:int, b:int, c:int) -> str:
        if a + b == c:
            return "+"
        elif a - b == c:
            return "-"
        else:
            return "0"

s = Solution()
print(s.solve(1, 2, 3))  # Output: "+"
print(s.solve(2, 9, -7))  # Output: "-"