@disallow('<STR_LIT:O>')<EOL>def nanargmax(values, axis=None, skipna=True, mask=None):
values, mask, dtype, _, _ = _get_values(<EOL>values, skipna, fill_value_typ='<STR_LIT>', mask=mask)<EOL>result = values.argmax(axis)<EOL>result = _maybe_arg_null_out(result, axis, mask, skipna)<EOL>return result<EOL>
Parameters
----------
values : ndarray
axis: int, optional
skipna : bool, default True
mask : ndarray[bool], optional
    nan-mask if known

Returns
--------
result : int
    The index of max value in specified axis or -1 in the NA case

Examples
--------
>>> import pandas.core.nanops as nanops
>>> s = pd.Series([1, 2, 3, np.nan, 4])
>>> nanops.nanargmax(s)
4