#!/bin/python3

import sys

def profit(b, s, c):
    i=0
    while i<c:
        if (c-i)==(b+s-i-i):
            return i
        i+=1
    # Return the fixed profit.

if __name__ == "__main__":
    t = int(input().strip())
    for a0 in range(t):
        b, s, c = input().strip().split(' ')
        b, s, c = [int(b), int(s), int(c)]
        result = profit(b, s, c)
        print(result)