Add GCD script (Task 1)

script_GCD.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+gcd() {
+    local a=$1 b=$2
+    while [ $b -ne 0 ]; do
+        local temp=$b
+        b=$((a % b))
+        a=$temp
+    done
+    echo $a
+}
+if [ $# -ne 2 ]; then
+    echo "Usage: $0 <num1> <num2>"; exit 1
+fi
+echo "НОД($1, $2) = $(gcd $1 $2)"