Shell Script to find biggest of three numbers using command line arguments

Program

#! /bin/bash
if [ $# -ne 3 ]
    then
	echo "$0: Numbers are not entered"
        exit 1
    fi
    n1=$1
    n2=$2
    n3=$3
    if [ $n1 -gt $n2 ] && [ $n1 -gt $n3 ]
    then
	echo "Number 1 is biggest: $n1"
    elif [ $n2 -gt $n1 ] && [ $n2 -gt $n3 ]
    then
	echo "Number 2 is biggest: $n2"
    elif [ $n3 -gt $n1 ] && [ $n3 -gt $n2 ]
    then
	echo "Number 3 is biggest: $n3"
    elif [ $1 -eq $2 ] && [ $1 -eq $3 ] && [ $2 -eq $3 ]
    then
	echo "All the three numbers are equal"
    else
        echo "Unable to determine"
    fi

Output 1

$ chmod 755 biggest-three-numbers-command-line.sh
$ sh biggest-three-numbers-command-line.sh 46 11 26
Number 1 is biggest: 46

Output 2

$ sh biggest-three-numbers-command-line.sh 6 65 32
Number 2 is biggest: 65

Output 3

$ sh biggest-three-numbers-command-line.sh 6 12 39
Number 3 is biggest: 39

Output 4

$ sh biggest-three-numbers-command-line.sh 8 8 8
All the three numbers are equal

Output 5

$ sh biggest-three-numbers-command-line.sh 18 32 32
Unable to determine