Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
	"unicode/utf8"
)

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	var strs []string
	var a, b, sum int64
	var digits int
	for scanner.Scan() {
		strs = strings.Split(scanner.Text(), " ")
		a, _ = strconv.ParseInt(strs[0], 10, 64)
		b, _ = strconv.ParseInt(strs[1], 10, 64)

		sum = a + b
		// goでlen(string)はbyte数が返る
		digits = utf8.RuneCountInString(strconv.FormatInt(sum, 10))

		fmt.Printf("%d\n", digits)
	}
}

C++: #include <iostream>

typedef struct _Data {
    int leftVal;
    int rightVal;
} Data;

typedef struct _DataList {
    int effectCount;
    Data dataList[200];
    int digitNumber[200];
} DataList;

class DigitNumber {
public:
    DigitNumber();
    // DigitNumber(const DigitNumber& other);
    // ~DigitNumber();

    bool Run();

private:
    bool ReadLine();
    bool Calc();
    void Show() const;

private:
    DataList m_DataList;
};

DigitNumber::DigitNumber()
{
    m_DataList = { 0 };
}

bool DigitNumber::Run()
{
    // Ignore return value
    (void)ReadLine();
    (void)Calc();
    Show();

    return true;
}

bool DigitNumber::ReadLine()
{
    int l = 0, r = 0;
    while (std::cin >> l >> r) {
        m_DataList.dataList[m_DataList.effectCount].leftVal = l;
        m_DataList.dataList[m_DataList.effectCount].rightVal = r;
        ++m_DataList.effectCount;
    }

    return true;
}

bool DigitNumber::Calc()
{
    unsigned int digitNumber = 0;
    unsigned int num = 0;

    for (int i = 0; i < m_DataList.effectCount; ++i) {
        digitNumber = 0;
        num = m_DataList.dataList[i].leftVal + m_DataList.dataList[i].rightVal;
        while (num != 0) {
            num /= 10;
            ++digitNumber;
        }
        m_DataList.digitNumber[i] = digitNumber;
    }
    return true;
}

void DigitNumber::Show() const
{
    for (int i = 0; i < m_DataList.effectCount; ++i) {
        std::cout << m_DataList.digitNumber[i] << std::endl;
    }
}

int main()
{
    DigitNumber digitNumber;
    digitNumber.Run();
}

C++: #include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define vec_input(v) for(auto it=v.begin();it!=v.end();it++){cin>>*it;}
#define vec_output(v) for(auto it=v.begin();it!=v.end();it++){if(it!=v.begin())cout<<" ";cout<<*it;}cout<<endl;
#define vec_debug(v) for(auto it=v.begin();it!=v.end();it++){cerr<<*it<<" ";}cerr<<endl;
#define yn(ans) cout<<(ans?"Yes":"No")<<endl
#define YN(ans) cout<<(ans?"YES":"NO")<<endl
using namespace std;
using ll = long long;
template <typename T>T digitsum(T n);
template <typename T>bool isPrime(T n);
template <typename T>vector<pair<T, T>> prime_factor(T n);
long long int intpow(long long int,long long int);
template <typename T>T intlog(T);
long long int combination(long long int,long long int);
long long int series_sum(long long int);

int main(){
    int a,b;
    while(scanf("%d %d",&a,&b)!=EOF){
        cout<<intlog(a+b)+1<<endl;
    }
}
template <typename T>T intlog(T x){
    string a=to_string(x);
    return a.length()-1;
}

C++: #include<stdio.h>
#define N 200

struct{int a,b;} d[N];

int main(){
    int i,j,l,s,k;
    for(i=0; i<N,scanf("%d %d",&d[i].a,&d[i].b)!=EOF; i++);
    l=i;
    for(i=0;i<l;i++){        
        s=d[i].a+d[i].b;
        for(j=1,k=0; s>=j; j*=10,k++);
        printf("%d\n",k);        
    }
    return 0;
}

C++: #include<iostream>
#include<stdio.h>
#include<math.h>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
    int a,b;
    while(cin>>a>>b){
        int c=a+b;
        int co=1;
        while(c/10){
            co++;
            c/=10;
        }
        cout<<co<<endl;
    }
}

C++: #include<iostream>
using namespace std;
int main(){
  for(int i=0;i<200;i++){
    int a,b,i=0;
    cin>>a>>b;
    int num=1;
    int c=a+b;
    while(c/10!=0){
      num++;
      c/=10;
    }
    cout<<num<<endl;
  }
  return 0;
}

C++: #include<iostream>
#include<cmath>
using namespace std;
 
int main()
{
    int a,b;
    while(cin>>a>>b)
    {
        a=log10(a+b)+1;
        cout<<a<<endl;
    }
    return 0;
}

C++: #include<iostream>
using namespace std;

int main(){
	int a[200],b[200],i=0,sum,count;
	while(cin>>a[i]){
		cin>>b[i];
		i++;
	}
	for(int j=0;j<i;j++){
		sum = a[j]+b[j];
		count = 0;
		while(sum != 0){
			sum/=10;
			count++;
		}
		cout<<count<<endl;
	}
    return 0;
}

C++: #include<iostream>
#include<stdio.h>
using namespace std;

int main(){
	int a,b,c,count=0;
	while(cin>>a>>b){
		count=0;
		 c=a+b;
		while(c!=0){
			c=c/10;
			count++;
		}
		cout<<count<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<math.h>

using namespace std;

int countDigit(int num){
	int i;
	for(i=1;pow(10,i)<=num;i++);
	return i;
}

int main(){
    int i,a,b;
    while(cin >> a >> b){
    	cout << countDigit(a+b) << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#include <cstdio>
using namespace std;

int a,b;

int main() {
  while (dainyuu() != EOF) {
    int i;
    a = a + b;
    while(a > 0) {
      a = a / 10;
      ++i;
    }
    
    cout << i << endl;
    
  }
}

int dainyuu() {
  cin >> a >> b;
}

C++: #include<iostream>
#include<vector>
#include<map>
#include<string>
using namespace std;

int get_digit(int num);

int main() {
	int first;
	int second;
	int data_cnt = 0;
	std::vector<int> inputs;

	while ((cin >> first >> second) || (data_cnt < 200)) {
		data_cnt++;
		inputs.push_back(first + second);
	}

	for (int i = 0; i < data_cnt; i++) {
		cout << get_digit(inputs[i]) << endl;
	}

	return 0;
}

int get_digit(int num) {
	unsigned digit = 0;
	while (num != 0) {
		num /= 10;
		digit++;
	}
	return digit;
}

C++: #include<iostream>
#include<queue>
#include<string>
#include<stack>
#include<cstdio>
#include<algorithm>

using namespace std;

int main(void)
{
  int i=0;
  int x=0,y=0;
  int sum=0;

  while(scanf("%d %d",&x, &y)!=EOF)
    {
      sum=x+y;
      i=1;
      while(sum>=10)
        {
          sum/=10;
          i++;
	}

      printf("%d\n", i);
    }
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#include<cstring>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define rp(a) while(a--)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
using namespace std;
typedef long long ll;
typedef vector<int> vi;
bool h[1000010]={false};
int main(){
	int a,b;
	while(cin>>a>>b){
		int c=a+b;
		int co=0;
		while(c){
			co++;
			c/=10;
		}
		cout<<co<<endl;
	}
}

C++: /*************************************************************************
	> File Name: qq.cpp
	> Author: ralph
	> Mail: 1694487365@qq.com
	> Created Time: 2018年12月21日 星期五 21时08分50秒
 ************************************************************************/

#include<bits/stdc++.h>
using namespace std;
int s[12];
int main()
{
    int a,b;
    while(cin>>a>>b)
    {
        int ans=0,now=a+b;
        while(now)
        {
            now/=10;
            ans++;
        }
        cout<<ans<<endl;
    }
}

C++: #include <stdio.h>

int main()
{
        int a, b, s, i, ii;

        while( EOF != scanf("%d %d", &a, &b) ){
                s = a + b;
                for(i=1, ii=0; i<=10000000; i*=10, ii++){
                        if( s < i ){
                                printf("%d\n", ii);
                                break;
                        }
                }
        }

        return 0;
}

C++: #include <iostream>
using namespace std;

int main(){
	int a,b,c;
	int ans;
	bool flg;
	int cnt=-1;
	
	while(cin>>a>>b){
		cnt++;flg=false;
		//-----test-----
		if(cnt==102) break;
		//--------------
		c=a+b;
		ans=1;
		while(10<=c){
			c/=10;
			ans++;
		}
		cout<<ans<<endl;
	}
	
	return 0;
}