Answer
The sorted list is $\{a, b, d ,f, k, m\}$. Please check the solution to have a look at how the algorithm would work.
Work Step by Step
The key property of the bubble sort is that at the end of iteration $i$, the last $i$ values would be in the correct position. For example, after the first iteration, the greatest value would be at the last location. During each iteration, for some value $m$ and all values of $i$ such that $i < m$, we check $a_i$ and $a_{i+1}$ and interchange if need be.
For this example, the list is $\{d, f, k, m, a ,b\}$.
Notice that in this example, the elements would be sorted according to lexicographic order (the order in the normal English alphabet).
During the first iteration, comparing each pair, we get the following - $\{d, f, k, a, b, m\}$. $m$ gets swapped twice (with $a$ and $b$) putting it at the end of the list.
During the second iteration, comparing each pair, we get the following - $\{d, f, a, b, k, m\}$. $k$ gets swapped twice (with $a$ and $b$) putting it at the second to last position.
During the third iteration, comparing each pair, we get the following $\{d, a, b, f, k, m\}$.$f$ gets swapped twice (with $a$ and $b$). Notice how each letter $\it{slides}$ to its position.
During the fourth iteration, comparing each pair, we get the following $\{ a, b, d, f, k, m\}$. $d$ gets swapped with $a$ and $b$ without any more changes needed.
In the last iteration, no changes are made to the list.
This example illustrates how even though the disorder among the set was borderline minimal (two sorted groups out of order), the algorithm needed multiple iterations to sort it properly.
