/in/foo.cc: In function 'int main()':
/in/foo.cc:10:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&N); len=0;
                 ^
/in/foo.cc:13:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    int L; scanf("%d%d",&pr[i].first,&L); pr[i].second=pr[i].first+L-1;
                                        ^