How to find repeated elements , numbers and corresponding values?

Hello everyone, i have matrices like that:

 1701595  1000
1704973  1000
1704973  1000
1713813  1000
1713812  1000
1713813  1000
1718216  1000
1718217  1000
1721276  1000
1730543  1000
1730544  1000
1733979  1000
1733978  1000
1754675  1000
1755167  1000
1764620  1000
1767147  1000
1767147  1000
1767146  1000
1768028  1000
1778080  1000
1792257  1000
1792257  1000
1803714  1000
1815437  1000
1820059  1000
1826840  1000
1828145  1000

as you see, there are some same elements in the first row, what i want is , as a third row is that if an element is repeated in the first row, delete the first one(s) row, just keep the last row and write how many times that element is repeated, and as a fourth row, lets say if it is repeated four time than the fourth column will be 4000 for this element, please can you give me an idea about how to do that?

[Adam]

You seem to be mixing up rows and columns in your question in numerous places, or I'm just misunderstanding what you want.

I assume you means there are some same elements in the first column and that you wish to put 4000 in the second column for a row that represents the 4th row with an identical value in the 1st column?

Answer 1

[Andrei Bobrov]

a = [1701595  1000
1704973  1000
1704973  1000
1713813  1000
1713812  1000
1713813  1000
1718216  1000
1718217  1000
1721276  1000
1730543  1000
1730544  1000
1733979  1000
1733978  1000
1754675  1000
1755167  1000
1764620  1000
1767147  1000
1767147  1000
1767146  1000
1768028  1000
1778080  1000
1792257  1000
1792257  1000
1803714  1000
1815437  1000
1820059  1000
1826840  1000
1828145  1000];

[~,b1,c1] = unique(a(:,1),'stable');
out = [a(b1,:) accumarray(c1,1)];