foo.c: In function 'main':
foo.c:4:21: error: invalid operands to binary & (have 'char *' and 'int')
    4 |  scanf("%d%d\n %d%d"&a1,&a2,&b1,&b2)
      |        ~~~~~~~~~~~~~^
      |        |
      |        char *
foo.c:4:37: error: expected ';' before 'm'
    4 |  scanf("%d%d\n %d%d"&a1,&a2,&b1,&b2)
      |                                     ^
      |                                     ;
    5 |  m=a1*a2;
      |  ~                                   
foo.c:11:4: error: 'else' without a previous 'if'
   11 |    else
      |    ^~~~
foo.c:12:3: error: break statement not within loop or switch
   12 |   break;
      |   ^~~~~
foo.c:3:23: warning: variable 'k' set but not used [-Wunused-but-set-variable]
    3 | { int a1,a2,b1,b2,i,j,k,m,n;
      |                       ^
foo.c:3:21: warning: variable 'j' set but not used [-Wunused-but-set-variable]
    3 | { int a1,a2,b1,b2,i,j,k,m,n;
      |                     ^

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