C :

#include <stdio.h>

int main()
{
	char s1[10] ; 
	scanf("%s",s1) ;
	int sum = 999999999 ;
	
	int length = 0 ;
	for(int i=0;s1[i]!='\0';i++)
	{
		++length ; 
	}
	int FirstNumber = 0 ; 
	
	for(int i=0;FirstNumber+1<length;i++)
	{
		int x=0,y=0 ;
		int shi = 1 ;
		for(int j=0;j<FirstNumber;j++)
			shi *= 10 ;
		for(int j=0;j<=FirstNumber;j++)
		{
			x += (s1[j]-48) * shi ;
			shi /= 10 ;
		}
		
		shi = 1 ;
		for(int j=FirstNumber+1;s1[j+1]!='\0';j++)
			shi *= 10 ;
		for(int j=FirstNumber+1;s1[j]!='\0';j++)
		{
			y += (s1[j]-48) * shi ;
			shi /= 10 ;
		}
		++FirstNumber ;
		
		int sign = 0 ;
		for(int j=2;j<x+y;j++)
		{
			for(int k=2;k<j;k++)
			{
				if((x+y)%k==0)
				{
					sign = 1 ;
					break ;
				}
			}
			if(sign==1)
				break ;
		}
		
		if(sign==0 && x+y<sum)
		{ 
			sum = x + y ;
		}
	}
	if(sum==999999999)
		printf("%d\n",-1) ;
	else 
		printf("%d\n",sum) ;
	return 0 ;
}

C++ :

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

long long zhuanhuan(string s){
	long long i,t = 1,n = 0;
	for (i = s.size() - 1;i >= 0;i--){
		n = n + (s[i] - 48) * t;
		t = t * 10;
	}
	return n;
}

bool sushu(long long n){
	bool f = true;
	long long i;
	for (i = 2;i <= sqrt(n);i++){
		if (n % i == 0){
			f = false;
			break;
		}
	}
	if (n == 1){
		f = false;
	}
	return f;
}

int main(){
	string s,s1,s2;
	cin>>s;
	long long i,a,b,min = 100000000;
	//12345
	for (i = 0;i < s.size() - 1;i++){
		s1 = s.substr(0,i + 1);
		s2 = s.substr(i + 1,s.size() - i - 1);
		a = zhuanhuan(s1);
		b = zhuanhuan(s2);
		if (sushu(a + b) && a + b < min){
			min = a + b;
		}
		//cout<<s1<<" "<<s2<<endl;
	}
	cout<<min;
}

Java :

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String n = sc.nextLine();
		int[] a = new int[n.length()-1];
		String x = "";
		for(int i = 0 ;i < a.length;i++){
			a[i] = Integer.parseInt(n.substring(0, i+1)) + Integer.parseInt(n.substring(i+1, n.length()));
			if(suShu(a[i])){
				x += a[i] +" ";
			}
			
		}
		
			try {
				String[] y = x.split(" ");
				int min = Integer.parseInt(y[0]);
				for(int i = 1;i < y.length;i++ ){
					if(min > Integer.parseInt(y[i])){
						min = Integer.parseInt(y[i]);
					}
				}
				System.out.println(min);
			} catch (NumberFormatException e) {
				System.out.println( "-1");
			}
		
	}
	public static boolean suShu(int a){
		boolean r = true;
		for(int i = 2;i <= a / 2;i++){
			if(a % i == 0){
				r = false;
				break;
			}
		}
		if( a == 1){
			r = false;
		}
		return r;
	}
}

Python :

import math
def suShu(n):
   f=  True
   for i in range(2,int(math.sqrt(n)) + 1 ):
      if n % i == 0:
         f = False
         break
   return f and n != 1

def chaiwei(n):
    min = 0  # min 存放2段之和最小的素数
    f = True  # 表示是否为第一次获取素数 
    for i in range(1,len(n)):
       x = int(n[0:i]) + int(n[i:])
       if suShu(x) :
          if f:
             min = x;
             f = False
          else:
             if x < min:
                min = x;
    return min

n = input();
r = chaiwei(n)
if r == 0:
    print(-1)
else:
    print(r)