用函数求四个数中的最大数

# include<stdio.h>
int main()
{int max4(int a,int b,int c,int d);
int a,b,c,d,max;
printf("Please enter 4 interger numbers:");
scanf("%d %d %d %d",&a,&b,&c,&d);
max=max4(a,b,c,d);
printf("max=%d\n",max);
return 0;
}
int max4(int a,int b,int c,int d)
{int max2(int a,int b);
int m;
m=max2(a,b);
m=max2(m,c);
m=max2(m,d);
return(m);
}
int max2(int a,int b)
{if(a>=b)
return a;
else
return b;
}