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River - viper

Viper - prize

Prize - pride

Pride - Price

Price × Creep

Creep - perch

Perch - retch

retch - chore

Chore -choke

Choke - Check

Check - cheek

Cheek × Hecks

Hecks × Shock

Shock - chose

Chose × Close

Close - Loose

Loose × Slope

Slope - spiel

Spiel - Plier

Plier × Repel

Repel - pears

Pears

Pearl

pearl - later

Later - trail

Trail -lairs

Lairs - stair

Stair - Strap

Strap - parse

Parse - Paste

Paste - waste