C++ Read a matrix from a file into a two dimensional array and ignore curly brackets and commas.

The file is in the format of {{row}, {row}, ....}The input file will look like this

input.txt:

a, b, c, d, e {{0, 0, 1, 0, 0}, {1, 0, 0, 1, 0}, {1, 0, 0, 0, 0}, {0, 1, 0, 0, 0}, {0,0,0,0,1}}

So I want to ignore the letters, the curly brackets, and the commas. Then just the numbers read into a two dimensional array to create an easily accessible 5x5 matrix.