ModAdd

#include<iostream>
#include<string>


int main(){
  std::cin.tie(NULL);
  std::ios_base::sync_with_stdio(0);
  std::string a,b;
  std::cin>>a>>b;
  int at_a,at_b;
  int lena=a.length()-1;
  int lenb=b.length()-1;
  for(int i=0;i<lenb-lena;i++){
    std::cout<<b[i];
  }
  for(int i=0;i<=lena;i++){
    int ii=lena-i;
    at_a=a[lena-ii]-'0';
    at_b=b[lenb-ii]-'0';
    std::cout<<(at_a+at_b)%10;
    
  }
  std::cout<<std::endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: RUNTIME ERROR

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: RUNTIME ERROR

Test 7

Verdict: ACCEPTED

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: RUNTIME ERROR

Test 10

Verdict: ACCEPTED