#include<stdio.h>
#include<string.h>
int dp[1005][1005];
char str1[1005],str2[1005];
int min(int a,int b,int c){
int min=a;
if(min>b) min=b;
if(min>c) min=c;
return min;
}
int main()
{
int n,m;
while(scanf("%d%s",&n,str1)==2){
scanf("%d%s",&m,str2);
for(int i=0;i<=n;i++)
dp[i][0]=i;//初始化str1前i个字符转化为str2的前0字符的操作数
for(int j=0;j<=m;j++)
dp[0][j]=j;//初始化str1前0个字符转化为str2的前j字符的操作数
int ok;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
str1[i-1]==str2[j-1]?ok=0:ok=1;
dp[i][j]=min(dp[i-1][j-1]+ok,dp[i-1][j]+1,dp[i][j-1]+1);
}
}
printf("%d\n",dp[n][m]);
}
return 0;
}
#include <iostream>
using namespace std;
#define MAXS 1010
char str1[MAXS],str2[MAXS];
int len1,len2;
int f[MAXS][MAXS]; //记录下str1取i个,str2取j个最少操作次数
int min(int a,int b){
return a<b?a:b;
}
int main(){
int i,j;
while(cin>>len2>>str2){
cin>>len1>>str1;
f[0][0] = 0;
for(i = 1;i <= len1;i++){
f[i][0] = i;
}
for(i = 1;i <= len2;i++){
f[0][i] = i;
}
for(i = 1;i <= len1;i++){
for(j = 1;j <= len2;j++){
int tmp = f[i - 1][j - 1] + (str1[i - 1]==str2[j - 1]?0:1);
tmp = min(f[i - 1][j] + 1,tmp);
f[i][j] = min(f[i][j - 1] + 1,tmp);
}
}
cout<<f[len1][len2]<<endl;
}
return 0;
}