Python || Easy Solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution(object):\n    def digitSum(self,s,k):\n        n=len(s)\n        while n>k:\n            s2=""\n            k1=k\n            for i in range(0,n,k):\n                s1=s[i:k1]\n                k1=k1+k\n                sum1=0\n                for j in s1:\n                    sum1=sum1+int(j)\n                s2=s2+str(sum1)\n            s=s2\n            n=len(s)\n        return s\n```
['Python']