#include "stdio.h"
#include "string.h"
#include "algorithm"
int main()
{
int k1, k2, len1,len2, i, j,a[27],sum,make;
char str1[100002], str2[100002];
while(scanf("%s %s",str1,str2)!=EOF)
{
k1=k2=0;sum=0;make=0;
for(i=0;i<26;i++)
{
a[i]=0;
}
while(str1[k1]) {a[str1[k1]-'A']++;k1++;}
while(str2[k2]) {a[str2[k2]-'A']++;k2++;}
for (i=0;i<26;i++)
{
if(a[i]%2==0) sum+=a[i];
else {sum+=a[i]-1;make=1;}
}
if(make==1) sum++;
printf("%d/n",sum);
}
return 0;
}