Slitherlink Floret Mystery Cache

This tiling was another new one on me (discovered when looking for tilings I had not used in the series so far). In the Floret tiling, all polygons have five sides (this is also true for the Cairo tiling, but the polygon shapes differ between the two tilings).

To work out the location of this cache, you need to do the following:

1. Solve the puzzle below (see the cache listing for Slitherlink Boot Camp for the rules about how to solve Slitherlink puzzles).
2. Locate the letters a through to r in the puzzle (h, i, l and o are omitted). For each letter, its numeric value is the number of lines around the cell.

The cache can be found at S 43 31.ABC E 172 34.DEF, where:

A = a + b
B = c + d + e
C = f + g
D = j + k
E = m + n + p
F = q + r

The checksum for A to F is 27.

The cache is a pill container in a camo bag, in a hole about waist height. Please recover well.

Note: this cache is one of the 20 puzzles that make up Master of Mystery #48 - Seoul