\[\boxed{\mathbf{51}.}\]
\[1)\ n > - 3:\]
\[n_{наим} = - 2.\]
\[2)\ n > 0\]
\[n_{наим} = 1.\]
\[3)\ n \geq 2\]
\[n_{наим} = 2.\]
\[4)\ n \geq - 5\]
\[n_{наим} = - 5.\]