как пишется правильно слово сирень или серень

дано натуральное четырехзначное число, верно ли, что  число начинается и заканчивается одной цифрой?

дано натурально 4значное число, верно ли что число заканчивается на цифру А(а вводится с клавиатуры)

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In modern global world more and more people are studying foreign languages. The question about the best way to do it provokes a lot of debate. Some people believe that it is impossible to become fluent in language without visiting it is native country. Others find it not obligatory.
I personally think that it is not a problem to learn a foreign language in their home country. There are a great number of possibilities for it. To begin with, every school and university today gives for students an opportunity to study a foreign language. Teachers and tutors in educational institutions do their best to help students to get knowledge. Besides, there is a number of language courses. They give a large choice of different programs. So you can choose the most suitable one according to your level and purposes. Furthermore, nowadays there is a wonderful opportunity to study using a computer. There is a large variety of educational programs and electronic dictionaries. Moreover, you can watch foreign films in the original.
But many people believe that the only way to have a good result at language studying is to communicate with native speakers. So they find it obligatory to study abroad. To my mind it is not necessarily thing. It is not difficult today to communicate with foreigners. Using the Internet you can chat with people from all over the world.
To sum it up, it seems to me that communication with native speakers is very important for those who want to master the language. But I see some ways to connect with them beside studying abroad.