def _sum(arr):
      
    sum=0
    for i in arr: 
        sum = sum + i      
    return(sum)  
def _sum(arr):
    sum = 0
   
    _i_i = 0
    while _i_i < len(arr):
        i = arr[_i_i]
        sum = sum + i
        _i_i += 1
    return sum