#include<stdio.h>
#include<string>
char a[101],b[101],aa[101],bb[101],c[101];
int i,j,k,l,n,m,l1,l2;
void gjd(int x,int y,int k)
{
	int i,j,n,m,p,q;
	if (x>l1-1&&y>l2-1) return;
	i=a[x]-48;
	j=b[y]-48;
	if (i<0) i=i+48;
	if (j<0) j=j+48;
	if (k==1) i--;
	if (i-j>=0) 
	{
		c[x]=(i-j)+48;
		k=0;
	}
    else
    {
    	c[x]=i-j+58;
    	k=1;
    }
    x=x+1;
    y=y+1;
    gjd(x,y,k);
}
main()
{
	FILE *f;
	f=fopen("sub.in","r");
	fscanf(f,"%s",aa);
	fscanf(f,"%s",bb);
	fclose(f);
	FILE *g;
	g=fopen("sub.out","w");
	l1=strlen(aa);
	l2=strlen(bb);
	for (i=0;i<l1;i++)
	a[i]=aa[l1-i-1];
    for (i=0;i<l2;i++)
    b[i]=bb[l2-i-1];
    gjd(0,0,0);
    l1=strlen(c);
    for (i=0;i<l1;i++)
    fprintf(g,"%c",c[l1-1-i]);
}