/in/foo.c: In function 'main':
/in/foo.c:4:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d",&n);
  ^~~~~
/in/foo.c:4:2: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:4:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:19:7: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
       printf("%d ",c[i]+c[j]);
       ^~~~~~
/in/foo.c:19:7: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:19:7: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:25:7: warning: incompatible implicit declaration of built-in function 'printf'
       printf("Inf");
       ^~~~~~
/in/foo.c:25:7: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:3:20: warning: unused variable 'm' [-Wunused-variable]
  int n,x,y,j=0,i=0,m;
                    ^