/in/foo.cc: In function 'int main()':
/in/foo.cc:25:1: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
 while(1);
 ^~~~~
/in/foo.cc:26:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
  scanf("%d%d",&N,&M);
  ^~~~~