Letters are pushed onto a stack in order shown below Specify where to insert the pop operations (shown by ) among the pushes of the given letters in order to produce the output shown below. You can only use the stack once for each letter. That means you cannot take any letter that were outputted from the stack and push them back on stack. If there is no solution say NONE DO NOT PUT ANY SPACES or COMMAS in your answer. 1 point penalty otherwise. letters push operation order: ESTUAR; all operations ( added): ; output: UATRSE