sol3.py

from functools import lru_cache
@lru_cache(None)
def abbreviation(a, b):
    def dp(i,j):
        if i==0 and j==0:return True
        if i==0:return False
        if j==0:
            if a[i-1].islower():return dp(i-1, j)
            else:return False
        if a[i-1]==b[j-1]:
            return dp(i-1, j-1)
        elif a[i-1].upper()==b[j-1]:
            return dp(i-1, j-1) or dp(i-1, j)
        elif a[i-1].islower():
            return dp(i-1, j)
        else:
            return False
    return 'YES' if dp(len(a),len(b)) else 'NO'