#include<iostream>

int digit(int a, int b){
  int digit=0;
  int c=a+b;
  
  if(c == 0){
    return 1;
  }
  else {
    while(c != 0){
      c /= 10;
      digit++;
    }
    return digit;
  }
}

int main(){
  int sum[200];
  int a, b; //2????????´??°
  int count=0; //????????????
    
  //std::cout << "Input two of numbers\n";
  
  while(std::cin >> a >> b){
    if(a == -1 && b== -1)
      break;
    
    sum[count]=digit(a,b);
    count++;
  }

  for(int i=0; i<count; i++){
    std::cout << sum[i] << '\n';
  }

  return 0;
}