站外题求助，悬关

#include<iostream>
#include<cmath>
using namespace std;
int wei(unsigned long long a){
  int p=0;
  for(;a;a/=10){
    p++;
  }
  return p;
}
int main(){
  unsigned long long a,b,aw,bw,cnt=0;
  cin>>a>>b;
  aw=wei(a);
  bw=wei(b);
    for (unsigned long long n=aw>bw?a:b; n>0; n--) {
        if(a%((unsigned long long)pow(10,n))/pow(10,(n-1))+b%(unsigned long long)pow(10,n)/pow(10,(n-1))>=10){
            cnt++;
        }
    }
    cout<<cnt;
  return 0;
}