import pandas as pd

data = {
    'name': ['Alice', 'Bob', 'Charlie', 'David', 'Eva', 'Frank'],
    'math': [90, 85, 76, 94, 80, 88]
}

df = pd.DataFrame(data)
print(df)

       name  math
0     Alice    90
1       Bob    85
2   Charlie    76
3     David    94
4       Eva    80
5     Frank    88

df = df.sort_values(by=['math'], ascending=False)
print(df)

       name  math
3     David    94
0     Alice    90
5     Frank    88
1       Bob    85
4       Eva    80
2   Charlie    76

n = int(len(df) * 0.5)
top_n = df.head(n)
print(top_n)

    name  math
3  David    94
0  Alice    90
5  Frank    88