stack<int> monotonically_decreasing;

// create monotonically decreasing stack

while (s.size()) {

int current_element = s.top();

s.pop();

if (monotonically_decreasing.size() == 0)

monotonically_decreasing.push(current_element);

else if (monotonically_decreasing.top() > current_element)

monotonically_decreasing.push(current_element);

else {

stack<int> temp;

while (monotonically_decreasing.size() and monotonically_decreasing.top() < current_element) {

temp.push(monotonically_decreasing.top());

monotonically_decreasing.pop();

}

monotonically_decreasing.push(current_element);

while (temp.size()) {

monotonically_decreasing.push(temp.top());

temp.pop();

}

}

}

// change the content of stack

while (monotonically_decreasing.size()) {

s.push(monotonically_decreasing.top());

monotonically_decreasing.pop();

}

}