#include <cstdint>
#include <iostream>
#include <sstream>
using namespace std;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
uint_fast64_t i, j;
stringstream inp;
inp << cin.rdbuf();
stringstream outp;
while(!(inp >> i >> j).eof()) {
if(i > j)
outp << i-j << '\n';
else
outp << j-i << '\n';
}
cout << outp.rdbuf();
}
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