/in/foo.cc: In function 'int main()':
/in/foo.cc:20:8: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  cin>>s+1;
       ~^~
/in/foo.cc:40:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(int i=1;i<=length;i++)
   ^~~
/in/foo.cc:47:4: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
    step++;
    ^~~~