The step function f(x) is graphed. On a coordinate plane, a step graph has horizontal segments that are each 1 unit long. The left end of each segment is a closed circle. The right end of each segment is an open circle. The left-most segment goes from (negative 5, 3) to (negative 4, 3). Each segment is 1 unit lower and 1 unit farther to the right than the previous segment. The right-most segment goes from (2, negative 4) to (3, negative 4).

What is the value of f(0)?