View Compilation Error

0_0_26084321_7406.cpp:26:10: error: '::main' must return 'int'
 int main(){
          ^
0_0_26084321_7406.cpp: In function 'int main()':
0_0_26084321_7406.cpp:31:4: error: expected ';' before 'if'
    if(op==1){
    ^
0_0_26084321_7406.cpp:52:1: error: expected '}' at end of input
 }
 ^
0_0_26084321_7406.cpp:52:1: error: expected '}' at end of input
0_0_26084321_7406.cpp:52:1: error: expected '}' at end of input