really easy to understandable solution guy's ->
\n\n# Complexity\n- Time complexity:O(n^2)\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# 
\n\n# Complexity\n- Time complexity:O(n^2)\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 {\n    public List<Integer> intersection(int[][] nums) {\n        HashMap<Integer, Integer>map=new HashMap<>();\n        for( int i=0; i<nums.length; i++)\n        {\n            for( int j=0; j<nums[i].length; j++)\n            {\n                if(map.containsKey(nums[i][j]))\n                {\n                    map.put(nums[i][j], map.get(nums[i][j])+1);\n                }\n                else\n                {\n                    map.put(nums[i][j], 1);\n                }\n            }\n        }\n         List<Integer>list=new ArrayList<>();\n        for( int i=0; i<nums[0].length; i++)\n        {\n            // System.out.println(nums[0][i]+" "+map.get(nums[0][i]));\n            if(map.get(nums[0][i])==nums.length)\n            {\n                list.add(nums[0][i]);\n            }\n        }\n        Collections.sort(list);\n        return list;\n    }\n}\n```
['Java']