计算1+2+3+..+n=？其中n通过键盘输入，累加和小于2的16次方。-Calculation 1+2+3+ ..+ n =? Where n is input through the keyboard, the sum is less than 2 ^ 16.-Calculation 1+2+3+ ..+n =? Where n is input through the keyboard, the sum is less than 2 ^ 16.-Calculation 1+2+3+ ..+ n =? Where n is input through the keyboard, the sum is less than 2 ^ 16.