C# easy solution.
\n# Complexity\n- Time complexity: 26 ms.Beats 62.7% of other solutions.\n Add your time complexity here, e.g. O(n) \n\n- Space complexity: 26.5 Mb.Beats 92.7% 
\n# Complexity\n- Time complexity: 26 ms.Beats 62.7% of other solutions.\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity: 26.5 Mb.Beats 92.7% of other solutions.\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\npublic class Solution {\n    public int MinimumSum(int num) {\n      int[] arr=new int[4];\n      int i=0;\n      while(i<4){\n      arr[i]=num%10;\n      num/=10;\n      i++;\n      }  \n      Array.Sort(arr);\n      return (arr[0]+arr[1])*10+arr[3]+arr[2];\n    }\n}\n```
['Array', 'Math', 'C#']