What is the intention of program below?
```
from collections import NAME_1
def p1(a, b):
    table = NAME_1()
    m = 0
    while (m < len(a)):
        n = 0
        while (n < len(b)):
            if not a[m] != b[n]:
                table[m, n] = table[m - 1, n] + 1
            n = n + 1
        m = m + 1
    if table:
        return max(table.values())
    else:
        return 0
``` The word "name_1" should not appear in your response.
user