View Compilation Error

0_0_18954531_21626.cpp: In function 'int main()':
0_0_18954531_21626.cpp:14:9: error: expected identifier before 'if'
         if(fst) --fst;
         ^
0_0_18954531_21626.cpp:14:22: error: expected ']' before ';' token
         if(fst) --fst;
                      ^
0_0_18954531_21626.cpp: In lambda function:
0_0_18954531_21626.cpp:14:22: error: expected '{' before ';' token
0_0_18954531_21626.cpp: In function 'int main()':
0_0_18954531_21626.cpp:15:9: error: 'else' without a previous 'if'
         else puts("");
         ^
0_0_18954531_21626.cpp:37:5: error: expected primary-expression before ']' token
     ]
     ^