View Compilation Error

0_0_14991211_15165.cpp: In function 'void solve()':
0_0_14991211_15165.cpp:28:9: error: 'bonus' was not declared in this scope
         bonus += a[i--] - b[j++];
         ^
0_0_14991211_15165.cpp:29:21: error: 'bonus' was not declared in this scope
     printf("%I64d", bonus);
                     ^