I noticed that it gives a right output till 32
That is, because the integer type you're using has 32 bits. It simply can't hold larger numbers. You can't solve it the conventional way.
Here's what I'd suggest: First let's estimate how many digits that number will have. Every time a number gets 10-fold in decimal writing a new digit is required. So the number of digits for a number in decimal is given by ceil(log10(n)). So for 2^1000 you need ceil(log10(2^1000)) digits, but that is just ceil(1000*log10(2)) = 302, so you'll need 302 decimal digits to write it down.
This gives the next idea: Write down the number 1 in 302 digits, i.e. 301 times '0' and one '1' in a string. Then double the string 1000 times, by adding it to itself just like in elementary school, carrying the overflowing digits.
EDIT I think I should point out, that the problem encountered is the whole point of this Project Euler problem. Project Euler problems all have in common, that you can not solve them by using naive programming methods. You must get creative to solve them!