Well, let's see, when computing the value for the maximal value for

subexpression (1,6), we tried all possible splittings

of the expression (1,6) into two subexpressions.

Well, let's just go through all of them.

The first possibility is to split it into two subexpressions (1,1),

which corresponds just to the first digit which

is just 5, and subexpression (2,6),

with a minus sign between them, right.

So for both these two subexpressions we already know minimal values and

maximal values.

Well, let me mark them.

So this is the minimal value for the subexpression (1,1).

This is the maximal value for subexpression (1,1).

For (2,6), this is the minimal value,

-195, and this is a maximal value, 75.

So we would like to maximize this subexpression

one minus subexpression two, which means that we would like the first subexpression

to be as large as possible and the second subexpression to be as small as possible.

Well, this means that we need to

try to take the maximal value of the first subexpression which is five and

the minimal value of the second subexpression which is -195.

Well, we see that in this case,

5 minus -195 is the same as 5 plus 195,

which equals exactly 200, right,

which allows us to conclude, actually,

that the value 200 can be obtained as follows.

So, we subtract the minimum value which is -195

over the second subexpression from 5, right.

So we restored the last operation in an optimal

parenthesizing of the initial expression.

However, we still need to find out how to obtain

-195 out of the second subexpression.

Well, let's do this.