对角线

遍历每个元素的左下、右下对角线，检查是否值相等

n,m = map(int,input().split())
A = []
for i in range(n):ls = list(map(int,input().split()))A.append(ls)cnt = 0
for i in range(n):for j in range(m):# zuoxiafor p in range(1, min(n-1-i +1,j+1)):if A[i+p][j-p]==A[i][j]:cnt +=1# youxiafor p in range(1, min(n-1-i+1, m-1-j+1)):if A[i+p][j+p] == A[i][j]:cnt+=1
print(cnt*2)