\[\boxed{\mathbf{348.}}\]
\[40 - 17 = 23\]
\[50 - 32 = 18\]
\[60 - 24 = 36\]
\[70 - 45 = 25\]
\[90 - 53 = 37\]
\[31 - 14 = 17\]
\[53 - 25 = 28\]
\[67 - 18 = 49\]
\[82 - 46 = 36\]
\[94 - 66 = 28\]
\[72 - 19 = 53\]
\[43 - 37 = 6\]
\[61 - 58 = 3\]
\[53 - 6 = 47\]
\[87 - 9 = 78\]