const N=16; b[0:N-1]:integer = (1,1,2,3,3,3,3,4,5,5,5,5,6,6,6,7); i,p:=1,1; do i<>N cand b[i-p]<>b[i] -> i:=i+1 | i<>N cand b[i-p]=b[i] -> i,p:=i+1,p+1 od