Easy soln, watch it understand it
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```cpp []
class Solution {
public:
    int minimumSum(vector<int>& nums) {
        int sum = INT_MAX;

        for(int i=0;i<nums.size()-2;i++){
            for(int j=i+1;j<nums.size()-1;j++){
                for(int k=j+1;k<nums.size();k++){
                    if(nums[i]<nums[j] && nums[k]<nums[j]){
                        int isum = nums[i]+nums[j]+nums[k];
                        sum = min(sum,isum);//min sum

                    }
                }
            }
        }
        return sum==INT_MAX?-1:sum;//if no sum elements satifies the cond then return -1.
        
    }
};
```
['C++']