1381

class CustomStack {
public:
    vector<int> stk, inc;
    int n;
    int min(int a, int b){
        return (a<b)?a:b;
    }
    CustomStack(int maxSize) {
        n = maxSize;
    }

    void push(int x) {
        if(stk.size() < n) {
            stk.push_back(x);
            inc.push_back(0);
        }
    }

    int pop() {
        int top, idx;
        idx = stk.size()-1;
        if(idx < 0) return -1;
        top = stk[idx];
        stk.pop_back();
        inc.pop_back();
        if(idx >= 1)
            inc[idx-1] += inc[idx];
        return (top+inc[idx]);
    }

    void increment(int k, int val) {
        k = min(k, stk.size())-1;
        if(k >= 0) inc[k] += val;
    }
};

/**
 * Your CustomStack object will be instantiated and called as such:
 * CustomStack* obj = new CustomStack(maxSize);
 * obj->push(x);
 * int param_2 = obj->pop();
 * obj->increment(k,val);
 */