\[\boxed{\mathbf{29.}}\]
\[100 - 12 = 100 - 10 - 2 =\]
\[= 90 - 2 = 88\]
\[100 - 23 = 100 - 20 - 3 =\]
\[= 80 - 3 = 77\]
\[100 - 41 = 100 - 40 - 1 =\]
\[= 60 - 1 = 59\]
\[100 - 35 = 100 - 30 - 5 =\]
\[= 70 - 5 = 65\]
\[100 - 56 = 100 - 50 - 6 =\]
\[= 50 - 6 = 44\]
\[100 - 68 = 100 - 60 - 8 =\]
\[= 40 - 8 = 32\]
\[100 - 74 = 100 - 70 - 4 =\]
\[= 30 - 4 = 26\]
\[100 - 83 = 100 - 80 - 3 =\]
\[= 20 - 3 = 17\]