Let s_{1}, s_{2}, ..., s_{101}be 101 bit strings of length at most 9. Prove that there exist two strings, s_{i}and s_{j}, where i not equal to j, that contain the same number of 0s and the same number of 1s. (eg: strings 001001 and 101000 contain the same number of 0s and the same number of 1s)