foo.c: In function 'main':
foo.c:6:45: error: expected ';' before 'printf'
    6 |   y=x%10*1000+x/10%10*100+x/100%10*10+x/1000
      |                                             ^
      |                                             ;
    7 |     printf("x=%d,y=d\n",x,y);
      |     ~~~~~~                                   
foo.c:4:9: warning: variable 'y' set but not used [-Wunused-but-set-variable]
    4 | { int x,y;
      |         ^

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