class Solution {
private:
    int minCostClimbingStairs(vector<int>& cost, int index) {
        if(index >= cost.size()) {
            return 0;
        }

        //going up one
        int costOne = minCostClimbingStairs(cost, index + 1);
        //going up two
        int costTwo = minCostClimbingStairs(cost, index + 2);


        return cost[index] + min(costOne, costTwo);
    }
public:
    int minCostClimbingStairs(vector<int>& cost) {
        int costStartFrom0 = minCostClimbingStairs(cost, 0);
        int costStartFrom1 = minCostClimbingStairs(cost, 1);

        return min(costStartFrom0, costStartFrom1);
    }
};