#include <stdio.h>
int stack[1000]={};
int top=-1;
void push(int x)
{
top++;
stack[top]=x;
}
int pop()
{
if(top==-1)
return -1;
else
return stack[top--];
}
int main()
{
char a[150]={}, b[150]={}, c=0;
int topa=0, topb=0, numa=0, numb=0, num=0;
scanf("%s %s", a, b);
topa=strlen(a)-1;
topb=strlen(b)-1;
while(1)
{
numa=numb=0;
if(topa!=-1)
{
numa=a[topa--]-'0';
}
if(topb!=-1)
{
numb=b[topb--]-'0';
}
if(numa<numb)
{
//a[topa]--;
//numa+=10;
strcpy(numa, numb);
}
num=numa-numb;
push(num);
if(topa==-1&&topb==-1)
{
break;
}
}
int zero_print=0;
int x=0;
while(top!=-1)
{
x=pop();
if(zero_print==0&&x!=0)
zero_print=1;
if(zero_print==1)
printf("%d", x);
}
if(zero_print==0&&x==0)
printf("0");
return 0;
}
/*
#include<stdio.h>
int main() {
char word1[1000] = "Hello";
char word2[1000] = "World";
char wordtemp[1000] = {0};
printf("%s %s\n", word1, word2);
strcpy(word1, wordtemp);
strcpy(word1, word2);
strcpy(wordtemp, word2);
printf("%s %s\n", word1, word2);
}
*/