if feet%2==0 and heads*2<=feet<=heads*4:
for chincken in range(heads+1):
rabbit=heads-chicken
if chicken*2+rabbit*4==feet:
print(f'有{chicken}只鸡,有{rabbit}只兔子)
else:
print('数据有误! 请重新输入')
heads=input('总头数:')
feet=input('总脚数:')
heads=int(heads)
feet=int(feet)
if feet%2==0 and heads*2=feet<=heads*4:
for chicken in range(heads+1):
rabbit=heads-chicken
if chicken *2+rabbit*4==feet:
print(f'有{chicken}只鸡,有{rabbit}只兔子')
else:
print('数据有误,请重新输入!')
if feet % 2 == 0 and heads*2 <= feet <= heads*4:
for chicken in range(heads+1):
rabbit = heads-chicken
if chicken * 2+rabbit*4==feet:
print(f" 有{chicken}鸡,{rabbit}兔")