Red Alert

Finally a monsoon has come. According to the Meteorological Department, there will be rain in the upcoming $N$ days in the city. Initially, the water level of the city is zero millimetres. The amount of rain on the $i$-th day can be described by an integer $A_i$ as follows: - If $A_i \gt 0$, the water level of the city increases by $A_i$ millimetres on the $i$-th day. - If $A_i = 0$, there is no