A DNA chain is a sequence of proteins of 4 types. The types are encoded using the characters 'A', 'C', 'G', 'T'. Two proteins are called
complementary if one is of type 'A' and the other is of type 'T', or if one is of type 'C' and the other is of type 'G'. Two DNA chains are called
complementary if they have equal length, and the i-th protein in the first chain and the i-th protein in the second chain are
complementary for all possible values of i.

You will be given strings first and second, representing two DNA chains of equal length. Your goal is to make the two chains complementary. To do this, you can perform a number of replacements, where each replacement involves changing a single protein in either one of the chains to a
different type. Return the minimum number of replacements required to achieve your goal.

输入格式

Each case contains two lines, that are the first and the second string: the first will contain between 1 and 50 characters, inclusive. And the second will contain the same number of characters as first. Each character in the first and the second string will be 'A', 'C', 'G' or 'T'.
Input ends with a single line of "#".

输出格式

For each case, output an integer on a single line, that is the minimum number of replacements required.

样例输入

ACGT
TGCA
ACGT
ACGT
ATAGTACCAC
CTTATTGGGT
#

样例输出

0
4
6

#include<stdio.h>
#include<string.h>
int main(){
    char str[2][55];
    int n,l,i;
    while(scanf("%s",str[0])){
    	if(str[0][0]=='#') break;
    	scanf("%s",str[1]);
    	n=0;
    	l=strlen(str[0]);
		for(i=0;i<l;i++){
			if(str[0][i]=='A'){
				if(str[1][i]!='T') n++;
			}
			else if(str[0][i]=='T'){
				if(str[1][i]!='A') n++;	
			}
			else if(str[0][i]=='C'){
				if(str[1][i]!='G') n++;
			}	
			else if(str[0][i]=='G')
				if(str[1][i]!='C') n++;	
		} 
		printf("%d\n",n);
	}
    return 0;
}