#include<stdio.h>
#include<string.h>
#define maxn 1010
int cmp(char *s1, char *s2){
while(s1[0]=='0' && strlen(s1)!=1)
strcpy(s1,s1+1);
while(s2[0]=='0' && strlen(s2)!=1)
strcpy(s2, s2+1);
int Len1 = strlen(s1), Len2 = strlen(s2), i, j, flag = 0, k;
if(Len1 == Len2 && strcmp(s1, s2)==0)
return 0;
else if(Len1 > Len2)
return 1;
else if(Len1 < Len2)
return -1;
else if(Len1 == Len2){
if(s1[0] > s2[0])
return 1;
else if(s1[0] < s2[0])
return -1;
else {
for(i = 1; i < Len1; i++){
if(s1[i] != s2[i])
flag = 1;
k = i;
break;
}
if(!flag)
return 0;
else if(flag && s1[k] > s2[k])
return 1;
else if(flag && s1[k] < s2[k])
return -1;
}
}
}
void sub(int *a, int *b, int len1){
int i, j;
for(i=0;i<len1;i++)
{
a[i]=a[i]-b[i];
if(a[i]<0)
{
a[i]+=10;
a[i+1]--;
}
}
i=len1-1;
while(a[i]==0)
{
i--;
}
for(j=i;j>=0;j--)
{
printf("%d",a[j]);
}
printf("\n");
}
int main()
{
char s1[maxn],s2[maxn];
while(scanf("%s%s",s1,s2)!=EOF)
{
int i,j,len1,len2;
int a[105]={0},b[105]={0};
len1=strlen(s1);
len2=strlen(s2);
for(i=len1-1,j=0;i>=0;i--,j++)
{
a[j]=s1[i]-48;
}
for(i=len2-1,j=0;i>=0;i--,j++)
{
b[j]=s2[i]-48;
}
if(cmp(s1, s2)==0)
printf("0\n");
else if(cmp(s1, s2)==1)
sub(a, b, len1);
else if(cmp(s1, s2)==-1)
sub(b, a, len2);
}
return 0;
}