https://www.acmicpc.net/problem/1890
n=int(input())
mlist=[list(map(int, input().split())) for _ in range(n)]
dp=[[0]*n for _ in range(n)]
dp[0][0]=1
for i in range(n):
for j in range(n):
if i==n-1 and j==n-1:
break
else:
if i+mlist[i][j]<n:
dp[i+mlist[i][j]][j]+=dp[i][j]
if j+mlist[i][j]<n:
dp[i][j+mlist[i][j]]+=dp[i][j]
print(dp[n-1][n-1])