C :

#include<stdio.h>
int main()
{
	int a,b,c,d,e,f,g;
	scanf("%d-%d-%d",&a,&b,&c);
	scanf("%d-%d-%d",&d,&e,&f);
		g=f-c-1;
	printf("%d",g);
	return 0;		
}

C++ :

#include<stdio.h>
int main()
{
    int a,b,c,e;
    scanf("%d-%d-%d",&a,&b,&c);
    scanf("%d-%d-%d",&a,&b,&e);
    printf("%d",e-c-1);
    return 0;
}

Java :

import java.util.Scanner;
public class Main {
    public static void main(String [] args){
        Scanner input=new Scanner(System.in);
        String s1=input.nextLine();
        String[] num1=s1.split("-");

        int x1=Integer.parseInt(num1[0]);
        int x2=Integer.parseInt(num1[1]);
        int x3=Integer.parseInt(num1[2]);
        String s2=input.nextLine();
        String[] num2=s2.split("-");
        int x4=Integer.parseInt(num2[0]);
        int x5=Integer.parseInt(num2[1]);
        int x6=Integer.parseInt(num2[2]);
        System.out.println((x6-x3-1));
    }
}

Python :

# coding=utf-8
#python2
a,b,c = raw_input().split('-')
c = int(c)
x,y,z = raw_input().split('-')
z = int(z)
print(z-c-1)

C# :

using System;
using System.Collections.Generic;
using System.Diagnostics.SymbolStore;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    internal class Program
    {
        static void Main()
        {
            int[] days = { 31,28,31,30,31,30,31,31,30,31,30,31};
            string[] a1 = Console.ReadLine().Split('-');
            int m1= Convert.ToInt32(a1[1]);
            int d1= Convert.ToInt32(a1[2]);
            string[] b1 = Console.ReadLine().Split('-');
            int m2 = Convert.ToInt32(b1[1]);
            int d2 = Convert.ToInt32(b1[2]);
            int y = 0;
            for (int i = m1 ; i < m2; i++) {
                y += days[i];
            }
            y += Math.Abs( d2 - d1-1);
            Console.WriteLine(y);
            Console.ReadKey();

        }

    }
}