/in/foo.c: In function 'main':
/in/foo.c:6:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d%d", &m, &n);
  ^~~~~
/in/foo.c:6:2: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:6:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:31:2: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
  printf("%d", end);
  ^~~~~~
/in/foo.c:31:2: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:31:2: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:28:7: warning: 't1' may be used uninitialized in this function [-Wmaybe-uninitialized]
    if (t1 == m&&t2==n)end++;
       ^