/in/foo.c: In function 'main':
/in/foo.c:12:20: error: 'atr2' undeclared (first use in this function); did you mean 'str2'?
   12 |         scanf("%s",atr2);
      |                    ^~~~
      |                    str2
/in/foo.c:12:20: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:13:16: warning: right-hand operand of comma expression has no effect [-Wunused-value]
   13 |         for(i=0,i<n;i++){
      |                ^
/in/foo.c:13:24: error: expected ';' before ')' token
   13 |         for(i=0,i<n;i++){
      |                        ^
      |                        ;
/in/foo.c:16:16: warning: right-hand operand of comma expression has no effect [-Wunused-value]
   16 |         for(j=0,j<m;j++){
      |                ^
/in/foo.c:16:24: error: expected ';' before ')' token
   16 |         for(j=0,j<m;j++){
      |                        ^
      |                        ;