PhoTronic
-3' -3 +4 -4' | -4 ob4 +5 -5 | ob5 +6 -6' -6 | ob6 -7 +7 od7 | -8 +8' +8 -9 | +9' +9 od9 -10 | +10'' -10 od9 +9 | +9' -9 +8 +8' | -8 od7 +7 -7 | ob6 -6 -6' +6 | ob5 -5 +5 ob4 | -4 -4' +4 -3 | -3'