import sys
import pandas as pd
for line in sys.stdin:
    a = line.split()
    print(int(a[0]) + int(a[1]))
df=pd.read_csv('Nowcoder.csv')
print(round(df['Num_of_exercise'].var(),2))
#round会在有效数字为0时省略显示，此时可以用:.2f  强行显示两位有效数字
print(f"{df['Number_of_submissions'].std():.2f}")