#include #include <math.h> #include #include <stdio.h> #include #include #include #include <string.h> #include using namespace std; #define LL long long const int N = 1e6 + 10; const int INF = 0x3f3f3f3f; string a,b; int a1[N],b1[N],c1[N],lena,lenb,lenc; int main() { cin >> a; cin >> b; lena = a.size(); lenb = b.size(); if(lena<lenb ||(lena == lenb&&a < b)) { swap(lena,lenb); swap(a,b); cout <<"-"; } for(int i = 0;i <lena;i++) { a1[i]= a[lena-i-1] -'0'; } for(int i = 0;i <lenb;i++) { b1[i]= b[lenb-i-1] -'0'; } lenc=lena; for(int i = 0;i <lenc;i++) { c1[i]=a1[i]-b1[i]; if(c1[i]<0) { a1[i + 1]--; c1[i]+=10; } } while(c1[lenc]==0&&lenc>0) lenc--; for(int i = lenc;i >= 0;i--) cout <<c1[i]; return 0; }