diff --git a/IM520/digit-E.png b/IM520/digit-E.png new file mode 100644 index 0000000000000000000000000000000000000000..a235adb61e266572435515016ae035eca98ca8e1 Binary files /dev/null and b/IM520/digit-E.png differ diff --git a/IM520/dot.png b/IM520/dot.png new file mode 100644 index 0000000000000000000000000000000000000000..ef6c7165e82ad25b4e28c9615daaab13a1e04407 Binary files /dev/null and b/IM520/dot.png differ diff --git a/IM520/minus.png b/IM520/minus.png new file mode 100644 index 0000000000000000000000000000000000000000..9385699c594ec9b4108065c813febb503e51d86e Binary files /dev/null and b/IM520/minus.png differ