import sys
line1=line2=None
for i, line in enumerate(sys.stdin):
line=line.strip()
if i%2==0:
line1=line
else:
line2=line
len1, len2=len(line1)+1, len(line2)+1
edit=[[i+j for j in range(len2)] for i in range(len1)]
for i in range(1, len1):
for j in range(1, len2):
if line1[i-1]==line2[j-1]:
edit[i][j]=edit[i-1][j-1]
else:
edit[i][j]=min(edit[i-1][j-1], edit[i-1][j], edit[i][j-1])+1
print(edit[len1-1][len2-1])