/*JUST INCREASE YOUR PROGRAM PERFORMANCE*/

#include<stdio.h>
#include<string.h>

int main()
{
int n,m,i,len;
int  a[26] = {0};
int  b[26] = {0};

char s1[1000],s2[1000],s3[1000];

gets(s1);
gets(s2);
gets(s3);
n = strlen(s1); m = strlen(s2);

for(i = 0;i<n;i++)
{
    a[s1[i] - 'A']++;
}

for(i = 0;i<m;i++)
{
    a[s2[i] - 'A']++;
}

len = strlen(s3); //YOU SHOULD USE A VARIABLE . IF YOU DONT USE VARIABLE , THE FUNCTION WILL EXECUTE EACH TIME. THAT WILL INCREASE YOUR TIME.
for(i = 0;i<len;i++)
{
    b[s3[i] - 'A']++;
}
int flag = 1;

for(i = 0;i<26;i++)
{
    if(a[i]!= b[i]) {
    flag = 0; break;
    }
}
if(flag) printf("YES");
else printf("NO");

return 0;
}