HTMLify

class Solution:
    def equalSumSpan(self, a1, a2):
        n = len(a1)
        first_occurrence = {0: -1}
        
        prefix_sum = 0
        max_len = 0
        
        for i in range(n):
            prefix_sum += (a1[i] - a2[i])
            
            if prefix_sum in first_occurrence:
                current_len = i - first_occurrence[prefix_sum]
                if current_len > max_len:
                    max_len = current_len
            else:
                first_occurrence[prefix_sum] = i
                
        return max_len