View Compilation Error

0_0_35974677_26619.cpp: In function 'int main()':
0_0_35974677_26619.cpp:4:2: error: '_int64' was not declared in this scope
  _int64 dp[40][40];
  ^
0_0_35974677_26619.cpp:7:3: error: 'dp' was not declared in this scope
   dp[i][0]=0;
   ^
0_0_35974677_26619.cpp:10:4: error: 'dp' was not declared in this scope
    dp[i][j]=dp[i-1][j]+dp[i][j-1];
    ^
0_0_35974677_26619.cpp:14:32: error: 'dp' was not declared in this scope
   printf("%d %d %I64d\n",m,n,2*dp[n][n]);
                                ^